What does this MR do?
Speed up todos queries by limiting the projects set we join with. Todo queries time in
dashboard/todos dropped from ~1.5 seconds to ~250ms for my account on production.
Are there points in the code the reviewer needs to double check?
Why was this MR needed?
Counting and/or listing all todos for a user can be slow if there are lots of projects he can access.
What are the relevant issue numbers?
Screenshots (if relevant)