(a) All claims equitable in nature upon which an action has been filed shall survive in favor of and against the heirs, successors, or personal representative of any deceased party to such an action.
(b) All claims equitable in nature upon which no action has been filed shall survive in favor of and against the personal representatives, heirs, or successors of deceased persons who, but for their death, could have enforced such claims or against whom such claims could have been enforced.