bench pallet: only require Hash instead of Block (#3244)

Preparation for https://github.com/paritytech/polkadot-sdk/issues/2664

Changes:
- Only require `Hash` instead of `Block` for the benchmarking
- Refactor DB types to do the same

## Integration

This breaking change can easily be integrated into your node via:  
```patch
- cmd.run::<Block, ()>(config)
+ cmd.run::<HashingFor<Block>, ()>(config)
```

Status: waiting for CI checks

---------

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>
Co-authored-by: Bastian Köcher <git@kchr.de>
Co-authored-by: cheme <emericchevalier.pro@gmail.com>

substrate/bin/node/cli/src/command.rs

@@ -28,6 +28,7 @@ use node_primitives::Block;
 use sc_cli::{Result, SubstrateCli};
 use sc_service::PartialComponents;
 use sp_keyring::Sr25519Keyring;
+use sp_runtime::traits::HashingFor;
 
 use std::sync::Arc;
 
@@ -106,7 +107,7 @@ pub fn run() -> Result<()> {
 							)
 						}
 
-						cmd.run::<Block, sp_statement_store::runtime_api::HostFunctions>(config)
+						cmd.run::<HashingFor<Block>, sp_statement_store::runtime_api::HostFunctions>(config)
 					},
 					BenchmarkCmd::Block(cmd) => {
 						// ensure that we keep the task manager alive