[Feature] Support STDC Network (new) (#995)

* refactor stdc code

* update key

* fix backbone inference

* remove comments

* fixing errors

* fixing version conflict

* fux typo

* use STDCHead

* upload models&logs

* adding model converters script and fix unittest

* fix error

* fix error

* fix error

* delete redundant keys in config

* fix errors in configs and unittest

* fix errors in configs and unittest

* fix errors in configs and unittest

* change Memory name

* refactor stdc2mmseg

* change name to STDC

* refactor stdc

* refactor stdc

* stdc refactor

* stdc refactor

* stdc refactor

* stdc refactor

* stdc refactor

* stdc refactor

* refactor stdc

* stdc refactor

Co-authored-by: xiexinch <xinchen.xie@qq.com>