refactor(tests): decouple unittests from integration tests (#15473)

* refactor move all tests to be under integration_tests package

* refactor decouple unittests from integration tests - commands

* add unit_tests package

* fix celery_tests.py

* fix wrong FIXTURES_DIR value

tests/integration_tests/fixtures/certificates.py

@@ -0,0 +1,38 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you 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.
+ssl_certificate = """-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----"""