1. Add F1 score to sequence classification metric
2. Fix a bug that the evaluate method in trainer does not support a pure pytorch_model.bin
3. Fix a bug in evaluation of veco trainer
4. Add some tips if lr_scheduler in the trainer needs a higher version torch
5. Add some comments
Link: https://code.alibaba-inc.com/Ali-MaaS/MaaS-lib/codereview/10532230