Use scale-encode and scale-decode to encode and decode based on metadata (#842)

* WIP EncodeAsType and DecodeAsType

* remove silly cli experiment code

* Get things finally compiling with EncodeAsType and DecodeAsType

* update codegen test and WrapperKeepOpaque proper impl (in case it shows up in codegen)

* fix tests

* accomodate scale-value changes

* starting to migrate to EncodeAsType/DecodeAsType

* static event decoding and tx encoding to use DecodeAsFields/EncodeAsFields

* some tidy up and add decode(skip) attrs where needed

* fix root event decoding

* #[codec(skip)] will do, and combine map_key stuff into storage_address since it's all specific to that

* fmt and clippy

* update Cargo.lock

* remove patched scale-encode

* bump scale-encode to 0.1 and remove unused dep in testing crate

* update deps and use released scale-decode

* update scale-value to latest to remove git branch

* Apply suggestions from code review

Co-authored-by: Alexandru Vasile <60601340+lexnv@users.noreply.github.com>

* remove sorting in derives/attr generation; spit them out in order given

* re-add derive sorting; it's a hashmap

* StaticTxPayload and DynamicTxPayload rolled into single Payload struct

* StaticStorageAddress and DynamicStorageAddress into single Address struct

* Fix storage address byte retrieval

* StaticConstantAddress and DynamicConstantAddress => Address

* Simplify storage codegen to fix test

* Add comments

* Alias to RuntimeEvent rather than making another, and prep for substituting call type

* remove unnecessary clone

* Fix docs and failing UI test

* root_bytes -> to_root_bytes

* document error case in StorageClient::address_bytes()

---------

Co-authored-by: Alexandru Vasile <60601340+lexnv@users.noreply.github.com>

subxt/src/storage/utils.rs

@@ -14,7 +14,7 @@ use crate::{
 
 /// Return the root of a given [`StorageAddress`]: hash the pallet name and entry name
 /// and append those bytes to the output.
-pub fn write_storage_address_root_bytes<Address: StorageAddress>(
+pub(crate) fn write_storage_address_root_bytes<Address: StorageAddress>(
     addr: &Address,
     out: &mut Vec<u8>,
 ) {
@@ -24,7 +24,7 @@ pub fn write_storage_address_root_bytes<Address: StorageAddress>(
 
 /// Outputs the [`storage_address_root_bytes`] as well as any additional bytes that represent
 /// a lookup in a storage map at that location.
-pub fn storage_address_bytes<Address: StorageAddress>(
+pub(crate) fn storage_address_bytes<Address: StorageAddress>(
     addr: &Address,
     metadata: &Metadata,
 ) -> Result<Vec<u8>, Error> {
@@ -35,7 +35,9 @@ pub fn storage_address_bytes<Address: StorageAddress>(
 }
 
 /// Outputs a vector containing the bytes written by [`write_storage_address_root_bytes`].
-pub fn storage_address_root_bytes<Address: StorageAddress>(addr: &Address) -> Vec<u8> {
+pub(crate) fn storage_address_root_bytes<Address: StorageAddress>(
+    addr: &Address,
+) -> Vec<u8> {
     let mut bytes = Vec::new();
     write_storage_address_root_bytes(addr, &mut bytes);
     bytes