The enumeration of particular powers by this charter shall not be held or deemed to be exclusive but, in addition to the powers enumerated therein, implied thereby, or appropriate to the exercise thereof, it is intended that the City of Piqua shall have, and may exercise, all powers which, under the constitution of Ohio, it would be competent for this charter specifically to enumerate. All powers of the city, whether expressed or implied, shall be exercised in the manner prescribed by this charter, or, if not prescribed therein, then in the manner provided by ordinance or resolution of the commission.