Add load_in_4bit option for OVModelForCausalLM (#538)
* Initial code for load_in_4_bit
* Dataset does not work
* Intermediate changes
* Make it working with dataset
* Style
* Fixed small issue
* Fixed failed tests
* Style
* Comment failed tests due to NNCF 2.8
* Commented failed tests until new NNCF release
* Added tests for load_in_4bit
* Added awq option. Included NNCF package into openvino extra.
* Rolled back including nncf into openvino extra
* Style
* Fixed tests
* Fixed issues with models larger than 1B. Added tests.
* Style
* Fixed issues. Applied comments.
* Removed unnecessary exception
* Applied more comments
* Fixed issue
* Make quantization_config a part of OVConfig in OVQuantizer
* Fixed issue with Transformers
* Fixed test
* Changed the naming. Added additional tests
* Fixed tests
* Fixed tests
* Applied more comments
* Style
