V2 UI: Search suggestions.

[oliverchang]

Add some autocompletion/suggestions to the search box

[zahraaalizadeh]

@another-rex Was wondering if you still want to work on this issue? otherwise I'll be happy to work on it.

[oliverchang]

This one is probably out of scope -- to do it well it would require a number of complicated backend changes (as well as possibly a DB stack migration).