feat: canvas auto mask followups 5

[psychedelicious]

Summary

• Rename Auto-Mask to Select Object.
• Change icon to shapes (open to suggestions - this is easily recognizable even at a small size):
  
• Add invert selection functionality via new field on the apply_tensor_mask_to_image node. This is by far the simplest way to support inverted selection. When the selection is inverted, it takes the size of the input layer. Demo:
  
  Screen.Recording.2024-10-25.at.5.11.18.pm.mov
• Increase size of layer toolbar icons slightly.
• Change filter icon to the "fill" variant, which has the same shape but is just a bit easier to recognize.
• Change the filter & select object Process buttons to use the "play" icon.
• Add Replace Current option to Select Object's Save As menu. Also upgraded Filter to have the same menu.
  

Related Issues / Discussions

offline discussion

QA Instructions

• Happy with the name Select Object?
• Happy with the "shapes" icon?
• Happy with the invert functionality?

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)