GitLab

* added a new test, passing without shared weights

* tested weight sharing

* added the test to test list file

* extended to world_size = 2

* fixed test

* [feat]: add limited and experimental support for shared parameter

* fixed tests

* simplify to work with layer with at least 1 non-shared params and add code to pick up linked_param field for sharding the shared param

* fixed the case where linked param is not in separate FSDP

* changelog and remove old code
Co-authored-by: Min Xu <min.xu.public@gmail.com>