PoV Reclaim Runtime Side (#3002)

# Runtime side for PoV Reclaim

## Implementation Overview
- Hostfunction to fetch the storage proof size has been added to the
PVF. It uses the size tracking recorder that was introduced in my
previous PR.
- Mechanisms to use the reclaim HostFunction have been introduced.
- 1. A SignedExtension that checks the node-reported proof size before
and after application of an extrinsic. Then it reclaims the difference.
- 2. A manual helper to make reclaiming easier when manual interaction
is required, for example in `on_idle` or other hooks.
- In order to utilize the manual reclaiming, I modified `WeightMeter` to
support the reduction of consumed weight, at least for storage proof
size.

## How to use
To enable the general functionality for a parachain:
1. Add the SignedExtension to your parachain runtime. 
2. Provide the HostFunction to the node
3. Enable proof recording during block import

## TODO
- [x] PRDoc

---------

Co-authored-by: Dmitry Markin <dmitry@markin.tech>
Co-authored-by: Davide Galassi <davxy@datawok.net>
Co-authored-by: Bastian Köcher <git@kchr.de>

cumulus/polkadot-parachain/src/service.rs

@@ -68,11 +68,15 @@ use substrate_prometheus_endpoint::Registry;
 use polkadot_primitives::CollatorPair;
 
 #[cfg(not(feature = "runtime-benchmarks"))]
-type HostFunctions = sp_io::SubstrateHostFunctions;
+type HostFunctions =
+	(sp_io::SubstrateHostFunctions, cumulus_client_service::storage_proof_size::HostFunctions);
 
 #[cfg(feature = "runtime-benchmarks")]
-type HostFunctions =
-	(sp_io::SubstrateHostFunctions, frame_benchmarking::benchmarking::HostFunctions);
+type HostFunctions = (
+	sp_io::SubstrateHostFunctions,
+	cumulus_client_service::storage_proof_size::HostFunctions,
+	frame_benchmarking::benchmarking::HostFunctions,
+);
 
 type ParachainClient<RuntimeApi> = TFullClient<Block, RuntimeApi, WasmExecutor<HostFunctions>>;
 
@@ -274,10 +278,11 @@ where
 		.build();
 
 	let (client, backend, keystore_container, task_manager) =
-		sc_service::new_full_parts::<Block, RuntimeApi, _>(
+		sc_service::new_full_parts_record_import::<Block, RuntimeApi, _>(
 			config,
 			telemetry.as_ref().map(|(_, telemetry)| telemetry.handle()),
 			executor,
+			true,
 		)?;
 	let client = Arc::new(client);