Improve team assignment support in several locations.

[eigood]

This makes use of changes in mantle-usl for teamAssignments, and does the proper entity-finds against teamMemberPartyId. With these changes, a logged-in user will be able to see Tasks, Projects, Milestones(inherited via Projects) and Requests that have been only assigned to a team, that the current user is a member of.

Requires moqui/mantle-usl#208