Implement crypto byte array newtypes in term of a shared type (#3684)

Introduces `CryptoBytes` type defined as:

```rust
pub struct CryptoBytes<const N: usize, Tag = ()>(pub [u8; N], PhantomData<fn() -> Tag>);
```

The type implements a bunch of methods and traits which are typically
expected from a byte array newtype
(NOTE: some of the methods and trait implementations IMO are a bit
redundant, but I decided to maintain them all to not change too much
stuff in this PR)

It also introduces two (generic) typical consumers of `CryptoBytes`:
`PublicBytes` and `SignatureBytes`.

```rust
pub struct PublicTag;
pub PublicBytes<const N: usize, CryptoTag> = CryptoBytes<N, (PublicTag, CryptoTag)>;

pub struct SignatureTag;
pub SignatureBytes<const N: usize, CryptoTag> = CryptoBytes<N, (SignatureTag, CryptoTag)>;
```

Both of them use a tag to differentiate the two types at a higher level.
Downstream specializations will further specialize using a dedicated
crypto tag. For example in ECDSA:


```rust
pub struct EcdsaTag;

pub type Public = PublicBytes<PUBLIC_KEY_SERIALIZED_SIZE, EcdsaTag>;
pub type Signature = PublicBytes<PUBLIC_KEY_SERIALIZED_SIZE, EcdsaTag>;
```

Overall we have a cleaner and most importantly **consistent** code for
all the types involved

All these details are opaque to the end user which can use `Public` and
`Signature` for the cryptos as before

substrate/frame/contracts/src/exec.rs

@@ -1466,14 +1466,14 @@ where
 
 	fn sr25519_verify(&self, signature: &[u8; 64], message: &[u8], pub_key: &[u8; 32]) -> bool {
 		sp_io::crypto::sr25519_verify(
-			&SR25519Signature(*signature),
+			&SR25519Signature::from(*signature),
 			message,
-			&SR25519Public(*pub_key),
+			&SR25519Public::from(*pub_key),
 		)
 	}
 
 	fn ecdsa_to_eth_address(&self, pk: &[u8; 33]) -> Result<[u8; 20], ()> {
-		ECDSAPublic(*pk).to_eth_address()
+		ECDSAPublic::from(*pk).to_eth_address()
 	}
 
 	#[cfg(test)]

substrate/frame/sassafras/src/benchmarking.rs

@@ -139,8 +139,8 @@ mod benchmarks {
 			TicketsIds::<T>::insert((epoch_tag as u8, i), id);
 			let body = TicketBody {
 				attempt_idx: i,
-				erased_public: EphemeralPublic([i as u8; 32]),
-				revealed_public: EphemeralPublic([i as u8; 32]),
+				erased_public: EphemeralPublic::from([i as u8; 32]),
+				revealed_public: EphemeralPublic::from([i as u8; 32]),
 			};
 			TicketsData::<T>::set(id, Some(body));
 		});
@@ -236,8 +236,8 @@ mod benchmarks {
 			.map(|i| {
 				let body = TicketBody {
 					attempt_idx: i,
-					erased_public: EphemeralPublic([i as u8; 32]),
-					revealed_public: EphemeralPublic([i as u8; 32]),
+					erased_public: EphemeralPublic::from([i as u8; 32]),
+					revealed_public: EphemeralPublic::from([i as u8; 32]),
 				};
 				let id_bytes = crate::hashing::blake2_128(&i.to_le_bytes());
 				let id = TicketId::from_le_bytes(id_bytes);

substrate/frame/support/test/tests/pallet_ui/storage_ensure_span_are_ok_on_wrong_gen.stderr

@@ -13,8 +13,8 @@ error[E0277]: the trait bound `Bar: WrapperTypeDecode` is not satisfied
    |
    = help: the following other types implement trait `WrapperTypeDecode`:
              Box<T>
-             Rc<T>
              frame_support::sp_runtime::sp_application_crypto::sp_core::Bytes
+             Rc<T>
              Arc<T>
    = note: required for `Bar` to implement `Decode`
    = note: required for `Bar` to implement `FullCodec`
@@ -65,8 +65,8 @@ error[E0277]: the trait bound `Bar: WrapperTypeEncode` is not satisfied
              bytes::bytes::Bytes
              Cow<'a, T>
              parity_scale_codec::Ref<'a, T, U>
-             Rc<T>
              frame_support::sp_runtime::sp_application_crypto::sp_core::Bytes
+             Rc<T>
              Arc<T>
              Vec<T>
            and $N others
@@ -106,8 +106,8 @@ error[E0277]: the trait bound `Bar: WrapperTypeDecode` is not satisfied
    |
    = help: the following other types implement trait `WrapperTypeDecode`:
              Box<T>
-             Rc<T>
              frame_support::sp_runtime::sp_application_crypto::sp_core::Bytes
+             Rc<T>
              Arc<T>
    = note: required for `Bar` to implement `Decode`
    = note: required for `Bar` to implement `FullCodec`
@@ -148,8 +148,8 @@ error[E0277]: the trait bound `Bar: WrapperTypeEncode` is not satisfied
              bytes::bytes::Bytes
              Cow<'a, T>
              parity_scale_codec::Ref<'a, T, U>
-             Rc<T>
              frame_support::sp_runtime::sp_application_crypto::sp_core::Bytes
+             Rc<T>
              Arc<T>
              Vec<T>
            and $N others
@@ -168,8 +168,8 @@ error[E0277]: the trait bound `Bar: WrapperTypeDecode` is not satisfied
    |
    = help: the following other types implement trait `WrapperTypeDecode`:
              Box<T>
-             Rc<T>
              frame_support::sp_runtime::sp_application_crypto::sp_core::Bytes
+             Rc<T>
              Arc<T>
    = note: required for `Bar` to implement `Decode`
    = note: required for `Bar` to implement `FullCodec`
@@ -210,8 +210,8 @@ error[E0277]: the trait bound `Bar: WrapperTypeEncode` is not satisfied
              bytes::bytes::Bytes
              Cow<'a, T>
              parity_scale_codec::Ref<'a, T, U>
-             Rc<T>
              frame_support::sp_runtime::sp_application_crypto::sp_core::Bytes
+             Rc<T>
              Arc<T>
              Vec<T>
            and $N others

substrate/frame/support/test/tests/pallet_ui/storage_ensure_span_are_ok_on_wrong_gen_unnamed.stderr

@@ -13,8 +13,8 @@ error[E0277]: the trait bound `Bar: WrapperTypeDecode` is not satisfied
    |
    = help: the following other types implement trait `WrapperTypeDecode`:
              Box<T>
-             Rc<T>
              frame_support::sp_runtime::sp_application_crypto::sp_core::Bytes
+             Rc<T>
              Arc<T>
    = note: required for `Bar` to implement `Decode`
    = note: required for `Bar` to implement `FullCodec`
@@ -65,8 +65,8 @@ error[E0277]: the trait bound `Bar: WrapperTypeEncode` is not satisfied
              bytes::bytes::Bytes
              Cow<'a, T>
              parity_scale_codec::Ref<'a, T, U>
-             Rc<T>
              frame_support::sp_runtime::sp_application_crypto::sp_core::Bytes
+             Rc<T>
              Arc<T>
              Vec<T>
            and $N others
@@ -106,8 +106,8 @@ error[E0277]: the trait bound `Bar: WrapperTypeDecode` is not satisfied
    |
    = help: the following other types implement trait `WrapperTypeDecode`:
              Box<T>
-             Rc<T>
              frame_support::sp_runtime::sp_application_crypto::sp_core::Bytes
+             Rc<T>
              Arc<T>
    = note: required for `Bar` to implement `Decode`
    = note: required for `Bar` to implement `FullCodec`
@@ -148,8 +148,8 @@ error[E0277]: the trait bound `Bar: WrapperTypeEncode` is not satisfied
              bytes::bytes::Bytes
              Cow<'a, T>
              parity_scale_codec::Ref<'a, T, U>
-             Rc<T>
              frame_support::sp_runtime::sp_application_crypto::sp_core::Bytes
+             Rc<T>
              Arc<T>
              Vec<T>
            and $N others
@@ -168,8 +168,8 @@ error[E0277]: the trait bound `Bar: WrapperTypeDecode` is not satisfied
    |
    = help: the following other types implement trait `WrapperTypeDecode`:
              Box<T>
-             Rc<T>
              frame_support::sp_runtime::sp_application_crypto::sp_core::Bytes
+             Rc<T>
              Arc<T>
    = note: required for `Bar` to implement `Decode`
    = note: required for `Bar` to implement `FullCodec`
@@ -210,8 +210,8 @@ error[E0277]: the trait bound `Bar: WrapperTypeEncode` is not satisfied
              bytes::bytes::Bytes
              Cow<'a, T>
              parity_scale_codec::Ref<'a, T, U>
-             Rc<T>
              frame_support::sp_runtime::sp_application_crypto::sp_core::Bytes
+             Rc<T>
              Arc<T>
              Vec<T>
            and $N others