[RSDK-12945] Add logic to return robot client itself when frame system is requested

[njooma]

RobotClient implements framesystem, so users don't actually need to call framesystem.FromProvider(machine). However, a user might find it confusing if they cannot use FromProvider like they can every where else. In the spirit of reducing the cognitive load and letting users get resources the same way across the board, calling framesystem.FromProvider on a RobotClient should return itself.