Create specific camera instances for different models

[cianmawhinney]

Cameras have different capabilities depending on the model, affecting the interpretation of values in the VISCA packets.

Proposal is to create a generic implementation, then extend it to customise it for each camera. The generic implementation should check the limits of the protocol itself, rather than being based on any hypothetical camera.

May also be better to define a single object for all of these constants so that defining new models can be easier in the future, rather than the current approach of defining them separately?

Camera models currently available for testing:

• PTZOptics PT20X-NDI
• PTZOptics PT20X-SDI
• PTZOptics PT30X-SDI
• Sony BRC-300P

Camera specific properties

• Pan angle multiplier
• Pan angle limits
• Tilt angle multiplier
• Tilt angle limits
• Zoom multiplier
• Zoom limits
• Iris stops
• Shutter speed values
• Gain values
• White balance presets