Find lines of code in a repo/directory via API and UI

Created by: dadlerj

Feature request description

Requested by a user at a customer:

Hi, is there a way to get the number of lines of code in a repo via the API?

Additional context

An alternative solution (or additional feature, depending on need) would be displaying this information in the UI via a Sourcegraph extension. Perhaps displaying output from https://github.com/boyter/scc in a given repo or directory on repo and directory pages.

UI

As a user who is not familiar with all of the repositories and who needs to review all code in multiple repositories, I want to be able to see the relative sizes of repositories. This will help me know how to divide up the work among my team and how to schedule the work.

https://github.com/AlDanial/cloc

Requested by @P3GLEG