Role s kategorií "Z" platí pro všechny kategorie začínající na Z

Closes #98.

mo/rights.py

@@ -144,7 +144,7 @@ class Rights:
         def try_role(role: db.UserRole, at: Optional[db.Place]):
             if ((at is None or role.place_id == at.place_id)
                     and (role.year is None or year is None or role.year == year)
-                    and (role.category is None or cat is None or role.category == cat)
+                    and (role.category is None or cat is None or role.category == cat or (role.category == 'Z' and cat.startswith('Z')))
                     and (role.seq is None or seq is None or role.seq == seq)
                     and (min_role is None or role_order_by_type[min_role] >= role_order_by_type[role.role])):
                 self.current_roles.append(role)