Support CIE 1931 XY color space

[Breina]

The spec does not currently seem to support XY colour space, even though some fixtures use this to configure their colour.

Example fixture: https://astera-led.com/wp-content/uploads/FP7_LunaBulb_DMX_Profiles_V4.pdf

Example using generic parameters: aputure/nova-p300c.json

Proposal

• Capability type: ColorXY
• Properties:

• • x (required), Parameter
• • y (required), Parameter