Cleanup overlapping codes for MiR/FM adapter

[xiyuoh]

Following the conversation in #33, currently there is a lot of code overlap between the RobotCommandHandle and fleet_adapter for both MiR and MiRFM adapters. There should be a base class for these codes so that the API classes can be passed to each adapter as necessary, plus there will not be a need for rewriting common functions or updating both scripts whenever there are updates.