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/__init__.py

@@ -0,0 +1,31 @@
+# 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.
+
+from .birth_names_dashboard import (
+    load_birth_names_dashboard_with_slices,
+    load_birth_names_dashboard_with_slices_module_scope,
+)
+from .energy_dashboard import load_energy_table_with_slice
+from .public_role import public_role_like_gamma, public_role_like_test_role
+from .unicode_dashboard import (
+    load_unicode_dashboard_with_position,
+    load_unicode_dashboard_with_slice,
+)
+from .world_bank_dashboard import (
+    load_world_bank_dashboard_with_slices,
+    load_world_bank_dashboard_with_slices_module_scope,
+)