Split both gags and masks out of collar slot.

This mr creates faceAccessory and mouthAccessory out of collar.

In my work, I found some odd quirks in collar.

1. There is a "ring gag" but it's rare. edit: now less rare.
2. There is a fuckdoll collar, but it's barely referred to, likely obsolete. now more obsolete
3. There are svgs apparently for "cat ears" collar. Assuming they work, I can imagine moving their display to the ear implants, or else make something new for the face slot.

Likely closes #1785 (closed), reopen if you want more.