[gha] split code gen unit tests out, bump unit test timeout by 10 minutes.
[gha] split code gen unit tests out, bump unit test timeout by 10 minutes.

Closes: #7782

libra/libra,aptos-labs/aptos-core,libra/libra,aptos-labs/aptos-core,libra/libra,aptos-labs/aptos-core,aptos-labs/aptos-core,aptos-labs/aptos-core,libra/libra,libra/libra,aptos-labs/aptos-core,aptos-labs/aptos-core