[RFC]: Add w8a8 Quantization

[dingdingchaomian]

Motivation.

支持使用modelslim工具生成的权重进行推理

Proposed Change.

修改量化相关实现

Feedback Period.

No response

CC List.

No response

Any Other Things.

No response

[wangxiyuan]

related issue and guide: #619

[learning-chip]

Incorrect output from W8A8 model: #628 (comment)

[tingyiz97]

Found a performance issue right here: #1015

[wangxiyuan]

No reply for long time. Feel free to create a new one if there is still any problem. I'll close this now