Refactor sp-sandbox; make sure both sandbox executors are always tested (#10173)

* sp-sandbox: convert executors into normal `mod`s instead of using `include!`

* sp-sandbox: run `cargo fmt` on `host_executor.rs`

* sp-sandbox: abstract away the executors behind traits

* sp_sandbox: always compile both executors when possible

* sc-executor: make sure all sandbox tests run on both sandbox executors

* sc-executor: fix brainfart: actually call into the sandbox through the trait

* sc-runtime-test: fix cargo fmt

* sc-runtime-test: deduplicate executor-specific sandbox test entrypoints

* sc-executor: test each sandbox executor in a separate test

* cargo fmt (Github's conflict resolving thingy broke indentation)

substrate/client/executor/src/integration_tests/mod.rs

@@ -71,6 +71,53 @@ macro_rules! test_wasm_execution {
 	};
 }
 
+/// A macro to run a given test for each available WASM execution method *and* for each
+/// sandbox execution method.
+#[macro_export]
+macro_rules! test_wasm_execution_sandbox {
+	($method_name:ident) => {
+		paste::item! {
+			#[test]
+			fn [<$method_name _interpreted_host_executor>]() {
+				$method_name(WasmExecutionMethod::Interpreted, "_host");
+			}
+
+			#[test]
+			fn [<$method_name _interpreted_embedded_executor>]() {
+				$method_name(WasmExecutionMethod::Interpreted, "_embedded");
+			}
+
+			#[test]
+			#[cfg(feature = "wasmtime")]
+			fn [<$method_name _compiled_host_executor>]() {
+				$method_name(WasmExecutionMethod::Compiled, "_host");
+			}
+
+			#[test]
+			#[cfg(feature = "wasmtime")]
+			fn [<$method_name _compiled_embedded_executor>]() {
+				$method_name(WasmExecutionMethod::Compiled, "_embedded");
+			}
+		}
+	};
+
+	(interpreted_only $method_name:ident) => {
+		paste::item! {
+			#[test]
+			fn [<$method_name _interpreted_host_executor>]() {
+				$method_name(WasmExecutionMethod::Interpreted, "_host");
+			}
+		}
+
+		paste::item! {
+			#[test]
+			fn [<$method_name _interpreted_embedded_executor>]() {
+				$method_name(WasmExecutionMethod::Interpreted, "_embedded");
+			}
+		}
+	};
+}
+
 fn call_in_wasm<E: Externalities>(
 	function: &str,
 	call_data: &[u8],