(a) Any person interested as or through an executor, administrator, trustee, guardian or other fiduciary, creditor, devisee, legatee, heir, next of kin, or beneficiary of a trust, in the administration of a trust, or of the estate of a decedent, a minor or person under legal disability, may have a declaration of rights or other legal relations in respect thereto:
(i) To ascertain any class of creditors, devisees, legatees, heirs, next of kin or others;
(ii) To direct the executors, administrators or trustees to do or abstain from doing any particular act in their fiduciary capacity; or (iii) To determine any question arising in the administration of the estate or trust, including questions of construction of wills and other writings.