[1/4][Refactor] Refactor torchair worker (#1885)

There is a lot torchair specified logic in common code. It results hard
code maintenance. We will create a new torchair module to launch
torchair related logic there. I plan to add 4 PR.

1. Refactor worker (this PR)
- create torchair module and move torchair related code in worker to the
new module
3. Refactor utils
4. Refactor model_runner
5. Refactor attention


- vLLM version: v0.9.2
- vLLM main:
8188196a1c

Signed-off-by: wangxiyuan <wangxiyuan1007@gmail.com>

tests/ut/test_platform.py

@@ -363,6 +363,16 @@ class TestNPUPlatform(TestBase):
             "vllm_ascend.worker.worker_v1.NPUWorker",
         )
 
+        test_ascend_config = self.mock_ascend_config
+        test_ascend_config.torchair_graph_config.enabled = True
+        mock_init_ascend.return_value = test_ascend_config
+        self.mock_vllm_config.parallel_config.worker_cls = "auto"
+        self.platform.check_and_update_config(self.mock_vllm_config)
+        self.assertEqual(
+            self.mock_vllm_config.parallel_config.worker_cls,
+            "vllm_ascend.torchair.torchair_worker.NPUTorchairWorker",
+        )
+
     @patch("vllm_ascend.ascend_config.check_ascend_config")
     @patch("vllm_ascend.ascend_config.init_ascend_config")
     @patch("vllm_ascend.utils.is_310p", return_value=True)