Axolotl Bucket Shield + Totem Respackopts V2

Fixes from prior version:
- Respackopts now uses real .json.rpo expansion files instead of ignored variant folders.
- Disabled options now switch the item back to the normal shield/totem model and stop Punchy from matching the item.
- Punchy bucket rendering now includes the real bucket bone, so it should show the full bucket, water, handle, and axolotl.

Requires Respackopts + LibJF for the menu, and Punchy for animated held models.
Place above the Refined/Fresh bucket pack.

V4 update:
- Fixed the Shield Default Icon option to use Minecraft's special shield renderer instead of a broken plain model reference.
- Added Custom Axolotl Icon as a GUI icon option for both shield and totem.
- Preserved this pack's existing pack.png and pack.mcmeta metadata.
