Add is_item_equipped_<item> placeholder

[Zadnik2]

Terms

• I'm using the very latest version of CosmeticsCore and its dependencies.
• I already searched on this Github page to check if the same suggestion was already reported.
• I already searched on the plugin wiki to know if the feature is already implemented.
• I already searched on the Discord server to know if anyone already has a solution for this or if the feature was already suggested.

Discord tag (optional)

No response

Describe the solution you'd like

Implement a placeholder is_item_equipped_ to check if an item is equipped for custom GUI building.

Is your feature request related to a problem?

I can't change the item/lore to an 'Equipped' item for the custom gui I am building for the plugin without this feature

Describe alternatives you've considered

No alternatives

Additional context

No response

[Zadnik2]

To add on this, if you see fit and have time this placeholder may also find use:

is_item_equipped_in_category_{category}

e.g. Is an item currently equipped in Hats, Balloons or Body section