rawdb: implement larry interface

[AL-CT]

Ensures RawDB adheres to the Larry interface while retaining its core functionalities. This will allow RawDB to be used with multiDB. Only the put, has, and get methods are available, in accordance with the original design. All other methods return a NotSupported error.

NOTE: further testing of multiDB with RawDB set up requires issue #19 to be addressed, and will be added in the future.