[impv] Add a unified field conversion method to convert python fields to java fields

[jieguangzhou]

There are many convert function in Task class

timeout
timeout_flag
is_cache
resource_list
environment_code

I think we can a better way to deal with it

[zhongjiajie]

I use meta class to refactor convert from java object to python model in src/pydolphinscheduler/models/meta.py but it still WIP