Add missing codegen mod in integration tests (#1418)

* add codgen mod to the module tree

* port codegen tests to scale-typegen

* remove test flag

testing/integration-tests/src/full_client/mod.rs

@@ -2,15 +2,10 @@
 // This file is dual-licensed as Apache-2.0 or GPL-3.0.
 // see LICENSE for license details.
 
-#[cfg(test)]
 mod blocks;
-#[cfg(test)]
 mod client;
-#[cfg(test)]
+mod codegen;
 mod frame;
-#[cfg(test)]
 mod metadata;
-#[cfg(test)]
 mod runtime_api;
-#[cfg(test)]
 mod storage;