[SD 3.5 Dreambooth LoRA] support configurable training block & layers (#9762)
* configurable layers
* configurable layers
* update README
* style
* add test
* style
* add layer test, update readme, add nargs
* readme
* test style
* remove print, change nargs
* test arg change
* style
* revert nargs 2/2
* address sayaks comments
* style
* address sayaks comments