Representer link counts introduce N+1 queries

[cavis]

We've been gradually tracking down / fixing N+1 queries via joins() and includes(). One are not tackled yet: link counts. For our internal users with 100s of accounts (ad-ops, support), this can be prohibitively slow.

Options:

• Tackle this with with caching (first query could still be real slow)
• Write a bunch of custom SQL to eager-load and hydrate those counts
• Use a query param similar to "zoom" to indicate if you want the counts returned or not
• Just remove counts from all the links (and fix Publish to work with that ... making a 2nd GET if it needs the count)