feat(ui): SDXL clip skip

[psychedelicious]

Summary

Uses the same CLIP Skip value for both CLIP1 and CLIP2.

Adjusted SDXL CLIP Skip min/max/markers to be within the valid range (0 to 11).

Related Issues / Discussions

Closes #4583

QA Instructions

• Try it out, with and without LoRAs (which have a minor graph change to support SDXL CLIP Skip). Shouldn't break anything.
• This does not change the default CLIP skip value. Don't think we should make a change like that.

Merge Plan

n/a

Checklist

• The PR has a short but descriptive title, suitable for a changelog
• Tests added / updated (if applicable)
• Documentation added / updated (if applicable)