(1) When declaratory relief is sought, all persons shall be made parties who have or claim any interest which would be affected by the declaration, and no declaration shall prejudice the rights of persons not parties to the proceeding. In any proceeding which involves the validity of a municipal ordinance or franchise, such municipality shall be made a party, and shall be entitled to be heard, and if the statute, ordinance or franchise is alleged to be unconstitutional, the Attorney General of the State shall also be served with a copy of the proceeding and be entitled to be heard.
(2) When declaratory relief is sought with respect to a tax, a person or group of persons challenging the tax shall provide a governmental entity and a school district whose direct revenue could be affected by the declaration with notice of the action by providing a copy of the complaint to the governmental entity or school district.
(3) A governmental entity or school district provided with notice under subdivision (b)(1) of this section has the right to intervene in the action but is not required to be named as a party to the action nor is the governmental entity or school district considered an indispensable or necessary party to the action.