Add unit test local cpu guide and enable base testcase (#1566)

### What this PR does / why we need it?
Use Base test and cleanup all manaul patch code
- Cleanup EPLB config to avoid tmp test file
- Use BaseTest with global cache
- Add license
- Add a doc to setup unit test in local env 

### Does this PR introduce _any_ user-facing change?
No

### How was this patch tested?
CI passed

Signed-off-by: Yikun Jiang <yikunkero@gmail.com>

tests/ut/patch/worker/patch_common/test_patch_distributed.py

@@ -1,3 +1,18 @@
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# This file is a part of the vllm-ascend project.
+#
+
 from tests.ut.base import TestBase
 
 

tests/ut/patch/worker/patch_common/test_patch_sampler.py

@@ -1,17 +1,20 @@
 import importlib
 import os
-import unittest
 from unittest import mock
 
 import torch
 from vllm.v1.sample.ops import topk_topp_sampler
 
+from tests.ut.base import TestBase
 
-class TestTopKTopPSamplerOptimize(unittest.TestCase):
+
+class TestTopKTopPSamplerOptimize(TestBase):
 
     @mock.patch.dict(os.environ, {"VLLM_ASCEND_ENABLE_TOPK_OPTIMIZE": "1"})
     @mock.patch("torch_npu.npu_top_k_top_p")
     def test_npu_topk_topp_called_when_optimized(self, mock_npu_op):
+        # We have to patch and reload because the patch will take effect
+        # only after VLLM_ASCEND_ENABLE_TOPK_OPTIMIZE is set.
         import vllm_ascend.patch.worker.patch_0_9_1.patch_sampler
         importlib.reload(vllm_ascend.patch.worker.patch_0_9_1.patch_sampler)