Finish get_by_term_id/get_by_slug/get_by_user_id methods on Profile

### Description

I would like to be able to lookup profiles by their term ID, slug, and user ID on the profile class. Right now these methods just return false.

These methods will require expensive queries so we should ensure these methods are performant and use caching.

### Use Case

When looking up a profile by term ID, slug, or user ID I should get back the proper profile if it exists.