* Fixed legacy extensions passing to MO tool.
* Added tests.
* Corrected test.
* Add debug print.
* Moved tests to layer tests.
* Added comment.
* Moved legacy ext tests to separate file. Fixed tmp .pb file cleaning.
* Small correction.
* Run MO Python API tests directory in CI.
* Small fix.
* Fix for case of splitted output.
* Corrected imports.
* Corrected imports.
* Added run of legacy extensions tests from subprocess.