Improve PTZ configuration detection

[caspermeijn]

• add supportContinuousPTZ flags for each driver to detect 'none' driver
• add supportsGoToHome and hasFixedHomePosition flags
• add HomeSupported to PTZNode
• copy PTZ spaces from the PTZNode to PTZConfiguration

[RogerHardiman]

Thanks for the PR and cleaning up the hard coded XML which, as you found, was duplicated in different places. That all goes back to the first days I got my Pan-Tilt-Hat for my Pi. There was so much to do implementing a NodeJS driver for the Pan-Tilt-Hat I never returned to clean up the RPOS code.

Feel free to tackle anything else in the code. I had thought about getting the ONVIF StorePreset command to ask the PTZ_Driver for the Pan-Tilt-Hat position and caching it and then when we have an ONVIF GotoPreset we can return to the correct Absolute position. We could even write the array to a JSON file (look at the code for writing v4l2crl.json to disk and the code for reading rposConfig.JSON) and load it back when the application first starts.

After that there is ONVIF Tours.

But maybe one step at a time.