[cameras.picam] Integrate and clean up driver

[natezb]

This driver needs to be integrated with the new parameter system introduced in version 0.4. More fundamentally, it needs to be modified to inherit from Camera and implement that interface.

[natezb]

This driver was updated (022f42eead8e485aff1d9a0e7e44dca44fb9f3b5) to use the new Sig/ArgHandler system introduced in NiceLib 0.5.

• [ ] Integrate with 0.4 parameter system
  • [ ] Replace PicamCamera.__init__ with an _initialize() method
• [ ] Implement the Camera interface for PicamCamera
  • [ ] Inherit from Camera
  • [ ] Utilize Camera.DEFAULT_KWDS and Camera._handle_kwds()
  • [ ] Implement width/height/max_width/max_height properties
  • [ ] Implement start_capture()
  • [ ] Implement get_captured_image()
  • [ ] Implement grab_image()
  • [ ] Implement start_live_video()
  • [ ] Implement stop_live_video()
  • [ ] Implement wait_for_frame()
  • [ ] Implement latest_frame()