code-substitute: Switch from `block_hash` to `block_number` (#10600)

* code-substitute: Switch from `block_hash` to `block_number`

This will make it easier for light clients to work with the code-substitute.

For more information on this see: https://github.com/paritytech/substrate/issues/10589

Closes: https://github.com/paritytech/substrate/issues/10589



* FMT

* Update client/service/src/client/wasm_substitutes.rs

Co-authored-by: André Silva <[email protected]>

* Update client/service/src/builder.rs

Co-authored-by: André Silva <[email protected]>

Co-authored-by: André Silva <[email protected]>