Use MO as module (#4801)

* Use MO as module

* Add legal notice

.github/workflows/mo.yml

@@ -85,7 +85,7 @@ jobs:
           wget -q http://download.tensorflow.org/models/mobilenet_v1_2018_08_02/mobilenet_v1_1.0_224.tgz
           tar -xf mobilenet_v1_1.0_224.tgz
           python3 -m pip install model-optimizer/dist/*.whl
-          python3 -c "import sys, subprocess, mo_tf; subprocess.run([sys.executable, mo_tf.__file__, '--input_model', 'mobilenet_v1_1.0_224_frozen.pb', '--input_shape', '[1,224,224,3]'], check=True)"
+          python3 -m mo --input_model mobilenet_v1_1.0_224_frozen.pb --input_shape "[1,224,224,3]"
 
       - uses: actions/upload-artifact@v2
         with:

model-optimizer/automation/package_BOM.txt

@@ -774,6 +774,7 @@ install_prerequisites/protobuf-3.6.1-py3.6-win-amd64.egg
 install_prerequisites/protobuf-3.6.1-py3.7-win-amd64.egg
 mo.py
 mo/__init__.py
+mo/__main__.py
 mo/back/__init__.py
 mo/back/ie_ir_ver_2/__init__.py
 mo/back/ie_ir_ver_2/emitter.py

model-optimizer/mo/__main__.py

@@ -0,0 +1,29 @@
+"""
+ Copyright (C) 2018-2021 Intel Corporation
+
+ 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.
+"""
+
+import sys
+
+from mo.utils.versions_checker import check_python_version  # pylint: disable=no-name-in-module
+
+ret_code = check_python_version()
+if ret_code:
+    sys.exit(ret_code)
+
+from mo.main import main
+from mo.utils.cli_parser import get_all_cli_parser  # pylint: disable=no-name-in-module
+
+sys.exit(main(get_all_cli_parser(), None))
+