Consolidate Location Tags as a subtype of Product Tags

[johnrozan]

As it stands now, product location effectively operates as a product tag, but it stands as a completely separate domain concept - we should at least discuss consolidating all tags pertaining to a product into a single domain concept, and discuss the implications for doing so (including how we'd change the DB, backend, and frontend).

We have a lot of somewhat complicated code that grabs all tag types and just mashes them together, using hard-coded indices and magic strings to demarcate the different types (for example, ProductFilter.tsx:67) - if we had a single interface for tags, we could simply return all desired tags including their subtype (i.e. location, role, user-defined, etc...) as part of a single request, instead of making 3 requests to 3 controllers and waiting for all 3 to return.

This would make adding new subtypes in the future easier, and also better prepare our codebase for if our users ever wanted the ability to define their own tag subtypes.