[examples] T2IAdapter training script (#4934)
* add t2i_example script
* remove in channels logic
* remove comments
* remove use_euler arg
* add requirements
* only use canny example
* use datasets
* comments
* make log_validation consistent with other scripts
* add readme
* fix title in readme
* update check_min_version
* change a few minor things.
* add doc entry
* add: test for t2i adapter training
* remove use_auth_token
* fix: logged info.
* remove tests for now.
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Co-authored-by: Sayak Paul <spsayakpaul@gmail.com>
