Insights: add admin mutation to enable or disable a specific series

Created by: coury-clark

Closes #26111 (closed)

Adds a mutation restricted to admins that allows enabling / disabling of specific series in code insights. This will be generally useful as a self service management tool to solve problematic queries.

I tested this:

1. with a unit test
2. by logging in as an admin and setting an enabled series to disabled and back to enabled, as well as enabled -> enabled and disabled -> disabled
3. by logging in as a non-admin and getting an authorization error