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

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

* Fix benchmark compilation

* Fix `cargo fmt`

* Fix compilation of another benchmark I've missed

* Cleanups according to review comments

* Move `max_memory_size` to `Semantics`

* Set `memory_guaranteed_dense_image_size` to `max_memory_size`

* Rename `wasm_instantiation_strategy` to `wasmtime_instantiation_strategy`

* Update the doc-comments regarding the instantiation strategy

* Extend the integration tests to test every instantiation strategy

* Don't drop the temporary directory until the runtime is dropped in benchmarks

* Don't drop the temporary directory until the runtime is dropped in tests

substrate/client/executor/wasmtime/src/lib.rs

@@ -38,5 +38,5 @@ mod tests;
 
 pub use runtime::{
 	create_runtime, create_runtime_from_artifact, prepare_runtime_artifact, Config,
-	DeterministicStackLimit, Semantics,
+	DeterministicStackLimit, InstantiationStrategy, Semantics,
 };