[1/N][Refactor] torchair model runner refactor

[wangxiyuan]

There is lot of torchair code in model runner leading the code hard for maintenance. We'll create new torchair_model_runner to split torchair related logic. Following the workflow #2203, this is the first PR.

What this PR does:

create the new torchair model runner, more function will be added later

• vLLM version: v0.10.0
• vLLM main: vllm-project/vllm@586f286

[github-actions]

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 76.34%. Comparing base (807f089) to head (2451598).
⚠️ Report is 613 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #2205   +/-   ##
=======================================
  Coverage   76.34%   76.34%           
=======================================
  Files         110      110           
  Lines       12473    12473           
=======================================
  Hits         9522     9522           
  Misses       2951     2951           

Flag	Coverage Δ
unittests	76.34% <ø> (ø)

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