* Remove "OV_FRONTEND_PATH" from `FrontEndManager`
* Remove "OV_FRONTEND_PATH" from layer_tests
* Remove "OV_FRONTEND_PATH" from find_ie_version.py
* Remove "OV_FRONTEND_PATH" from .ci/
* Move `ov::get_plugin_path` to file_util.hpp (ov::util)
* Add `register_front_end(name, path)` FEM public API
* Enable frontend/ tests
* ClangFormat
* Remove OV_FRONTEND_PATH from FE shared utils
* Add `register_front_end()` to PythonAPI
* Update Py tests with registering of "mock_py" FE
* ClangFormat
* Leftovers
* Fix SegFault with `register_front_end(name, lib_path)`
* Add FE_LIB_PRE and FE_LIB_SUFFIX to `ov_core_unit_tests`
* Fix format
* Update `testFailRegisterFEByWrongPath`
* refactor of renaming libraries in layer tests
* 1. adds check for old API and new FE usafe
2. refactor of api_2 arg
* fix for tf_NMS test preprocessing
* take libs path from LD_LIBRARY_PATH env
* convert str to Path object
* use wheels path to libs
* print lib paths
* print lib paths
* use ov_frontend_path env
* also check if file to rename exists
* removes redundant prints
* copy instead of rename
* 1. copy instead of rename
2. adds some details to readme
* tf_fe lib renaming to switch to new fe
* Apply suggestions from code review
* 1. implements renaming for win os
2. --api_2 key is equal to True by default
* --ir_version key is equal to '11' by default
* resolves merge conflicts
* check if file to rename exists
Co-authored-by: Evgenya Stepyreva <eva.my.link@gmail.com>
Vitaliy Urusovskij