contracts: Allow contracts to dispatch calls into the runtime (#9276)

* contracts: Allow contracts to dispatch calls into the runtime

* Fix RPC tests

* Fix typo

* Replace () by AllowAllFilter and DenyAllFilter

* Add rust doc

* Fixup for `()` removal

* Fix lowest gas calculation

* Rename AllowAllFilter and DenyAllFilter

* Updated changelog

substrate/frame/example-parallel/src/tests.rs

@@ -44,7 +44,7 @@ parameter_types! {
 }
 
 impl frame_system::Config for Test {
-	type BaseCallFilter = ();
+	type BaseCallFilter = frame_support::traits::AllowAll;
 	type Origin = Origin;
 	type Call = Call;
 	type PalletInfo = PalletInfo;