[main]Refactoring w4a8 and w8a8 and supporting deepseek w4a8

[pichangping]

What this PR does / why we need it?

Does this PR introduce any user-facing change?

How was this patch tested?

[codecov]

Codecov Report

Attention: Patch coverage is 25.29412% with 127 lines in your changes missing coverage. Please review.

Project coverage is 31.89%. Comparing base (c30ddb8) to head (c922b10).
Report is 36 commits behind head on main.

Files with missing lines	Patch %	Lines
vllm_ascend/quantization/w4a8_dynamic.py	24.42%	99 Missing ⚠️
vllm_ascend/quantization/quant_config.py	0.00%	12 Missing ⚠️
vllm_ascend/quantization/w8a8_dynamic.py	16.66%	10 Missing ⚠️
vllm_ascend/models/deepseek_v2.py	40.00%	3 Missing ⚠️
vllm_ascend/quantization/quantizer.py	75.00%	2 Missing ⚠️
vllm_ascend/quantization/w8a8.py	50.00%	1 Missing ⚠️

❌ Your patch check has failed because the patch coverage (25.29%) is below the target coverage (100.00%). You can increase the patch coverage or adjust the target coverage.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1469      +/-   ##
==========================================
+ Coverage   27.39%   31.89%   +4.49%     
==========================================
  Files          56       61       +5     
  Lines        6191     6704     +513     
==========================================
+ Hits         1696     2138     +442     
- Misses       4495     4566      +71     

Flag	Coverage Δ
unittests	31.89% <25.29%> (+4.49%)	⬆️

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[github-actions]

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