Training register custom hooks

[ggggg111]

At the current state, custom hooks from config files are not registered. E.g.:

cfg.custom_hooks = [
    dict(
        type='CustomHook1',
        priority='HIGHEST',
        # args [...]
    )
]

This can be easily solved by modifying the current train_model function after registering the standard hooks (see https://github.com/kennymckormick/pyskl/blob/main/pyskl/apis/train.py#L117).