PoV Reclaim (Clawback) Node Side (#1462)

This PR provides the infrastructure for the pov-reclaim mechanism
discussed in #209. The goal is to provide the current proof size to the
runtime so it can be used to reclaim storage weight.

## New Host Function
- A new host function is provided
[here](https://github.com/skunert/polkadot-sdk/blob/5b317fda3be205f4136f10d4490387ccd4f9765d/cumulus/primitives/pov-reclaim/src/lib.rs#L23).
It returns the size of the current proof size to the runtime. If
recording is not enabled, it returns 0.

## Implementation Overview
- Implement option to enable proof recording during import in the
client. This is currently enabled for `polkadot-parachain`,
`parachain-template` and the cumulus test node.
- Make the proof recorder ready for no-std. It was previously only
enabled for std environments, but we need to record the proof size in
`validate_block` too.
- Provide a recorder implementation that only the records the size of
incoming nodes and does not store the nodes itself.
- Fix benchmarks that were broken by async backing changes
- Provide new externalities extension that is registered by default if
proof recording is enabled.
- I think we should discuss the naming, pov-reclaim was more intuitive
to me, but we could also go with clawback like in the issue.

## Impact of proof recording during import
With proof recording: 6.3058 Kelem/s
Without proof recording: 6.3427 Kelem/s

The measured impact on the importing performance is quite low on my
machine using the block import benchmark. With proof recording I am
seeing a performance hit of 0.585%.

---------

Co-authored-by: command-bot <>
Co-authored-by: Davide Galassi <davxy@datawok.net>
Co-authored-by: Bastian Köcher <git@kchr.de>

substrate/client/service/src/builder.rs

@@ -130,10 +130,11 @@ where
 }
 
 /// Create the initial parts of a full node with the default genesis block builder.
-pub fn new_full_parts<TBl, TRtApi, TExec>(
+pub fn new_full_parts_record_import<TBl, TRtApi, TExec>(
 	config: &Configuration,
 	telemetry: Option<TelemetryHandle>,
 	executor: TExec,
+	enable_import_proof_recording: bool,
 ) -> Result<TFullParts<TBl, TRtApi, TExec>, Error>
 where
 	TBl: BlockT,
@@ -148,7 +149,26 @@ where
 		executor.clone(),
 	)?;
 
-	new_full_parts_with_genesis_builder(config, telemetry, executor, backend, genesis_block_builder)
+	new_full_parts_with_genesis_builder(
+		config,
+		telemetry,
+		executor,
+		backend,
+		genesis_block_builder,
+		enable_import_proof_recording,
+	)
+}
+/// Create the initial parts of a full node with the default genesis block builder.
+pub fn new_full_parts<TBl, TRtApi, TExec>(
+	config: &Configuration,
+	telemetry: Option<TelemetryHandle>,
+	executor: TExec,
+) -> Result<TFullParts<TBl, TRtApi, TExec>, Error>
+where
+	TBl: BlockT,
+	TExec: CodeExecutor + RuntimeVersionOf + Clone,
+{
+	new_full_parts_record_import(config, telemetry, executor, false)
 }
 
 /// Create the initial parts of a full node.
@@ -158,6 +178,7 @@ pub fn new_full_parts_with_genesis_builder<TBl, TRtApi, TExec, TBuildGenesisBloc
 	executor: TExec,
 	backend: Arc<TFullBackend<TBl>>,
 	genesis_block_builder: TBuildGenesisBlock,
+	enable_import_proof_recording: bool,
 ) -> Result<TFullParts<TBl, TRtApi, TExec>, Error>
 where
 	TBl: BlockT,
@@ -225,6 +246,7 @@ where
 					SyncMode::LightState { .. } | SyncMode::Warp { .. }
 				),
 				wasm_runtime_substitutes,
+				enable_import_proof_recording,
 			},
 		)?;