Reference key storage api (#447)

* codegen: Update polkadot.rs

polkadot commit-hash: d96d3bea85
polkadot tag: v0.9.16-rc2

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* codegen: Reference key storage api

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* codegen: Regenerate polkadot.rs with reference api

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* tests: Update tests with reference interface

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* cli: Fix polkadot.rs license check

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* codegen: Update polkadot.rs with copyright

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* Revert "codegen: Update polkadot.rs with copyright"

This reverts commit 2970d0573dc0b11d01072b270a525ad497992ddf.

Revert "cli: Fix polkadot.rs license check"

This reverts commit 6fe8818582ae39669c059c1ed0424b6606620295.

* codegen: Implement AccountData trait in the expected order

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* codegen: Store implementation of StorageEntry

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* codegen: Generate AccountDefaultData wrapper struct

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* codegen: Allow `Account` references

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* codegen: Update polkadot.rs

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* codegen: Utilize AccountDefaultData instead of Account

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* codegen: Update polkadot.rs

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* tests: Update tests to utilize `Account` reference

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* codegen: Rename AccountDefaultData to AccountOwned

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* codegen: Add comments for wrapper account

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* codegen: Obtain vector type parameter for TypePath::Type

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* codegen: Use slices instead of `& std::vec` in storage API

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* codegen: Update polkadot.rs

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* codegen: Fix documentation

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* tests: Remove extra reference

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* examples: Add staking example to exercise storage API

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* codegen: Update polkadot.rs

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* tests: Update storage tests

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* Fix cargo clippy

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* codegen: Simplify vec_type_param

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* examples: Rename staking_details.rs to fetch_staking_details.rs

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* tests: Remove dummy variable

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* examples: Update polkadot version

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* Apply rust-fmt

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* codegen: Regenerate polkadot.rs

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

* examples: Remove comment

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

subxt/tests/integration/storage.rs

@@ -55,7 +55,7 @@ async fn storage_map_lookup() -> Result<(), subxt::Error<DispatchError>> {
         .await?;
 
     // Look up the nonce for the user (we expect it to be 1).
-    let entry = ctx.api.storage().system().account(alice, None).await?;
+    let entry = ctx.api.storage().system().account(&alice, None).await?;
     assert_eq!(entry.nonce, 1);
 
     Ok(())
@@ -79,7 +79,7 @@ async fn storage_n_mapish_key_is_properly_created(
     };
 
     // This is what the generated code hashes a `session().key_owner(..)` key into:
-    let actual_key_bytes = KeyOwner(KeyTypeId([1, 2, 3, 4]), vec![5u8, 6, 7, 8])
+    let actual_key_bytes = KeyOwner(&KeyTypeId([1, 2, 3, 4]), &[5u8, 6, 7, 8])
         .key()
         .final_key(StorageKeyPrefix::new::<KeyOwner>())
         .0;
@@ -132,7 +132,7 @@ async fn storage_n_map_storage_lookup() -> Result<(), subxt::Error<DispatchError
         .api
         .storage()
         .assets()
-        .approvals(99, alice, bob, None)
+        .approvals(&99, &alice, &bob, None)
         .await?;
     assert_eq!(entry.map(|a| a.amount), Some(123));
     Ok(())