feat: HeadDB Integration

[TheSilentPro]

Adds native HeadDB support to DeluxeMenus.

This adds a new headdb- item hook, so menus can use heads from the HeadDB plugin directly in item materials.

Example:

items:
  example:
    material: "headdb-1"
    slot: 13
    display_name: "&cHeadDB Head"

[BlitzOffline]

Hello. Please apply the 2 changes requested for the PR to be approved and merged.