Add MatchCategory()

[veechs]

What will your feature request solve?

Having a way for Categories to make matching decisions based on the outcome of others can unlock some interesting possibilities.

• A custom Category can exclude or include the matches of a built-in Category.
• Categories would become reusable functions, so if one had a list using Zone(), multiple other Categories could use that list without needing to maintain it multiple places.

Describe the solution you'd like

MatchCategory(<CategoryID>)

• Will require exposing IDs in the UI somewhere.
• Also will need protection against loops (1 references 2 references 1…).

Additional context

^{I don’t know for sure whether anyone will use this, but it also just seems like a natural addition.}