Transaction versioning in the RuntimeVersion (#5582)

* Add transaction_version

* Semantic versioning for runtimes

* Move new field to bottom

* Versioning

* Runtime versioning stuff.

* Fix test

* Adds tests and fixes bugs

* Bump runtime

Co-authored-by: Bastian Köcher <git@kchr.de>

substrate/frame/system/src/lib.rs

@@ -1617,6 +1617,7 @@ mod tests {
 			spec_version: 1,
 			impl_version: 1,
 			apis: sp_version::create_apis_vec!([]),
+			transaction_version: 1,
 		};
 	}