Implement a few team endpoints for APIv4 (#5296)

* Implement GET /teams/{team_id} endpoint for APIv4

* Implement GET /users/{user_id}/teams endpoint for APIv4

* Implement GET /teams/{team_id}/members/{user_id} endpoint for APIv4

api/team.go

@@ -82,7 +82,7 @@ func GetAllTeamListings(c *Context, w http.ResponseWriter, r *http.Request) {
 	m := make(map[string]*model.Team)
 	for _, v := range teams {
 		m[v.Id] = v
-		if !app.HasPermissionTo(c.Session.UserId, model.PERMISSION_MANAGE_SYSTEM) {
+		if !app.SessionHasPermissionTo(c.Session, model.PERMISSION_MANAGE_SYSTEM) {
 			m[v.Id].Sanitize()
 		}
 	}