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/test_utils.py

@@ -1,4 +1,17 @@
-import vllm_ascend.patch.worker.patch_common.patch_utils  # type: ignore[import]  # isort: skip  # noqa
+#
+# 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.
+#
 
 import math
 import os
@@ -10,10 +23,11 @@ import torch
 from vllm.config import (CompilationConfig, ModelConfig, ParallelConfig,
                          VllmConfig)
 
+from tests.ut.base import TestBase
 from vllm_ascend import utils
 
 
-class TestUtils(unittest.TestCase):
+class TestUtils(TestBase):
 
     def test_is_310p(self):
         utils._IS_310P = None