Make Move Project Dropdown Performant

Currently the move project dropdown works with an async ajax call (thanks @iamphill). The call itself is still very non performant. I see 2 options:

1. improve the query itself. At some point (n) it will be too many projects, so there is a limit here.
2. remote lookup for the search of the dropdown and infinite scrolling.

cc @yorickpeterse @iamphill @DouweM @dblessing