Make API backwards compatible with CC (#1697)

* Rework how a runtime api calls into the runtime

Now we generate a default implementation for each api call that calls
a generated method `method_runtime_api_impl`. This newly generated
method is the one that will be implemented by the `impl_runtime_apis`
macro in the runtime for the client side.

* Support `changed_in` to change runtime api function signatures

* Update documentation

* Fixes tests

* Implement checking the api version with a predicate

* Make the implementation backwards compatible with CC

* Update wasm files after merge

* Check for wasm runtime differences by building master and current branch

* Update spec_version and wasm files

* Fixes

* Revert my changes

* Remove `patch.crates-io` from test-runtime

substrate/core/sr-version/src/lib.rs

@@ -136,6 +136,16 @@ impl RuntimeVersion {
 			s == &A::ID && *v == A::VERSION
 		})
 	}
+
+	/// Check if the given api is implemented and the version passes a predicate.
+	pub fn has_api_with<A: RuntimeApiInfo + ?Sized, P: Fn(u32) -> bool>(
+		&self,
+		pred: P,
+	) -> bool {
+		self.apis.iter().any(|(s, v)| {
+			s == &A::ID && pred(*v)
+		})
+	}
 }
 
 #[cfg(feature = "std")]