Kerui cameras: support more dps.
- support a camera switch in place of the separate "privacy" switch (logic reversed)
- add additional optional dps that were not handled in the original config
For Kerui 300W, add additional optional dp for resolution_change,
found in almost identical Fuers 5MP camera, making it a
100% match. Also add the image to the motion event as a string, as at
least the Fuers camera does not provide a usable snapshot for the
camera. Issue #2410