Switch to pooling copy-on-write instantiation strategy for WASM (companion for Substrate#11232) (#5337)

* Switch to pooling copy-on-write instantiation strategy for WASM

* Fix compilation of `polkadot-test-service`

* Update comments

* Move `max_memory_size` to `Semantics`

* Rename `WasmInstantiationStrategy` to `WasmtimeInstantiationStrategy`

* Update a safety comment

* update lockfile for {"substrate"}

Co-authored-by: parity-processbot <>