* fix(factory.py): handle qs:.. in mime type
Fixes https://github.com/BerriAI/litellm/issues/11839
* feat(litellm_proxy/): don't transform messages client-side
leave litellm proxy messages untouched - allow proxy to handle transformation
prevents double transformation
* feat(tag_management_endpoints.py): support adding models to tag by adding model_name
Closes https://github.com/BerriAI/litellm/issues/11884
* test(test_tag_management_endpoints.py): add unit tests for adding new model by public model name
* test: update test