(a) In cases of actual controversy, the respective superior courts of this state shall have power, upon petition or other appropriate pleading, to declare rights and other legal relations of any interested party petitioning for such declaration, whether or not further relief is or could be prayed; and the declaration shall have the force and effect of a final judgment or decree and be reviewable as such.
(b) In addition to the cases specified in subsection (a) of this Code section, the respective superior courts of this state shall have power, upon petition or other appropriate pleading, to declare rights and other legal relations of any interested party petitioning for the declaration, whether or not further relief is or could be prayed, in any civil case in which it appears to the court that the ends of justice require that the declaration should be made; and the declaration shall have the force and effect of a final judgment or decree and be reviewable as such.
(c) Relief by declaratory judgment shall be available, notwithstanding the fact that the complaining party has any other adequate legal or equitable remedy or remedies.