Improve CodeExecutor (#2358)

Since `sp-state-machine` and `GenesisConfigBuilderRuntimeCaller` always
set `use_native` to be false.
We should remove this param and make `NativeElseWasmExecutor` behave
like its name.
It could make the above components use the correct execution strategy.

Maybe polkadot do not need about `NativeElseWasmExecutor` anymore. But
it is still needed by other chains and it's useful for debugging.

---------

Co-authored-by: Bastian Köcher <git@kchr.de>
Co-authored-by: command-bot <>
Co-authored-by: Michal Kucharczyk <1728078+michalkucharczyk@users.noreply.github.com>

substrate/primitives/core/src/traits.rs

@@ -51,7 +51,6 @@ pub trait CodeExecutor: Sized + Send + Sync + ReadRuntimeVersion + Clone + 'stat
 		runtime_code: &RuntimeCode,
 		method: &str,
 		data: &[u8],
-		use_native: bool,
 		context: CallContext,
 	) -> (Result<Vec<u8>, Self::Error>, bool);
 }