Fix TeamManager.get_for_user()'s hiding of non-visible teams.

Move the filtering of non-visible teams to where the results
dict is constructed, otherwise non-visibile teams may be returned
if either access_groups or SENTRY_PUBLIC are True.
Merge pull request #1316 from jaysoffian/async_ui_team_delete

Fix TeamManager.get_for_user()'s hiding of non-visible teams.