[Feature] Support DeepFloyd IF

[okotaku]

Motivation

Support DeepFloyd IF

Results (Optional)

deepfloyd_if_xl_dreambooth_lora_dog

Stage1 output example

Stage3 output example

deepfloyd_if_l_pokemon_blip

Stage1 output example

Stage3 output example

Checklist

Before PR:

• Pre-commit or other linting tools are used to fix the potential lint issues.
• Bug fixes are fully covered by unit tests, the case that causes the bug should be added in the unit tests.
• The modification is covered by complete unit tests. If not, please add more unit test to ensure the correctness.
• The documentation has been modified accordingly, like docstring or example tutorials.