Auto parse argument of mlchain run to mlconfig

[lamhoangtung]

Priority order:

• ENV Var
• mlchain run arg
• mlconfig.yaml value

Note: default group in mlconfig should be effect by this as well

[lamhoangtung]

To parse argument defined in mlconfig env section:

mode:
  default: general
  env:
    idcard:
      weight: './models/card.pt'
    general:
      weight: './models/general.pt'

You can do this now:

mlchain run kws --weight='hihi'

All args after kws will be able to override value define in mlconfig file or environment variable.

BTW, environment variable and args parsed by mlchain run CLI are now able to override default group as well