Improve admin analytics with events + top repository CTAs

Created by: macraig

Discuss and implement code navigation admin analytics backend work needed to implement design

Admin analytics page should now show a list of top five repositories by volume of code intel events (sorted). For each repo we must know how many languages are associated with it and if said language has precise events, what % of results for that language are currently precise. If for a language in a repo they don’t use precise BUT a precise indexer exists, option to enable/info. For languages we don’t support, display a call to action to request.