Added strict=False for load_from_checkpoint (Lightning-AI#2819)

* Added strict=False and hparams_file accepcts dict

* Apply suggestions from code review

Co-authored-by: Justus Schock <12886177+justusschock@users.noreply.github.com>

* Type check fix

* Added tests

* Linting & test fix

* Removed redundant code & test

* Added strict=False and hparams_file accepcts dict

* Apply suggestions from code review

Co-authored-by: Justus Schock <12886177+justusschock@users.noreply.github.com>

* Type check fix

* Added tests

* Linting & test fix

* Removed redundant code & test

* Apply suggestions from code review

* tests

* tests

* chlog

* Update tests/models/test_restore.py

Co-authored-by: Rohit Gupta <rohitgr1998@gmail.com>

* update test comments

* Added docstring for the strict attribute

* Added supplementary tests

* Update saving.py

* Apply suggestions from code review

Co-authored-by: Rohit Gupta <rohitgr1998@gmail.com>

* pep8, removed extra func

Co-authored-by: Jirka Borovec <Borda@users.noreply.github.com>
Co-authored-by: Justus Schock <12886177+justusschock@users.noreply.github.com>
Co-authored-by: Jirka Borovec <jirka@pytorchlightning.ai>
Co-authored-by: Rohit Gupta <rohitgr1998@gmail.com>
Co-authored-by: Adrian Wälchli <aedu.waelchli@gmail.com>
Co-authored-by: ananyahjha93 <ananya@pytorchlightning.ai>