Implement runtime version checks in set_code (#4548)

* Implement runtime version checks in `set_code`

Check that the new runtime code given to `set_code` fullfills some
requirements:

- `spec_name` matches
- `spec_version` does not decreases
- `impl_version` does not decreases
- Either `spec_version` and `impl_version` increase

* Make tests almost work

* Some fixes after master merge

* Fix tests

* Add missed file

* Make depedency check happy?

* Remove leftover `sc-executor`

* AHHHHH

* Reset debug stuff

* Remove some 'static

* More 'static

* Some docs

* Update `Cargo.lock`

substrate/primitives/core/src/traits.rs

@@ -80,7 +80,7 @@ sp_externalities::decl_extension! {
 }
 
 /// Code execution engine.
-pub trait CodeExecutor: Sized + Send + Sync {
+pub trait CodeExecutor: Sized + Send + Sync + CallInWasm + Clone + 'static {
 	/// Externalities error type.
 	type Error: Display + Debug + Send + 'static;
 
@@ -99,3 +99,30 @@ pub trait CodeExecutor: Sized + Send + Sync {
 		native_call: Option<NC>,
 	) -> (Result<crate::NativeOrEncoded<R>, Self::Error>, bool);
 }
+
+/// Something that can call a method in a WASM blob.
+pub trait CallInWasm: Send + Sync {
+	/// Call the given `method` in the given `wasm_blob` using `call_data` (SCALE encoded arguments)
+	/// to decode the arguments for the method.
+	///
+	/// Returns the SCALE encoded return value of the method.
+	fn call_in_wasm(
+		&self,
+		wasm_blob: &[u8],
+		method: &str,
+		call_data: &[u8],
+		ext: &mut dyn Externalities,
+	) -> Result<Vec<u8>, String>;
+}
+
+sp_externalities::decl_extension! {
+	/// The call-in-wasm extension to register/retrieve from the externalities.
+	pub struct CallInWasmExt(Box<dyn CallInWasm>);
+}
+
+impl CallInWasmExt {
+	/// Creates a new instance of `Self`.
+	pub fn new<T: CallInWasm + 'static>(inner: T) -> Self {
+		Self(Box::new(inner))
+	}
+}