Combine many Image components into one struct ImageFormat

[emilk]

• Blocked by Move code-generated enum from union to int type. #7022

See #6386 (comment) for more

archetype Image {
	buffer: ImageBuffer,
	format: ImageFormat
}

archetype SegmentationImage {
	buffer: ImageBuffer,
	format: ImageFormat,
}

archetype DepthImage {
	// Required:
	buffer: ImageBuffer,
	format: ImageFormat,
	
	meter: Optional<…>,
	colormap: Optional<…>,
}

component ImageFormat {
	datatype ImageFormat;
}

datatype ImageFormat {
	width: uint,
	height: uint,

	pixel_format: Optional<PixelFormat>, // Optional or not?
	color_model: Option<ColorModel>, // used if pixel_format = ARRAY
	datatype: Option<ChannelDatatype> // used if pixel_format = ARRAY
}

component enum PixelFormat {
    /// See `ColorModel` and `ChannelDatatype` instead
	ARRAY,

	RGB_565,
	RGBA_8888,
	NV12,
	YUY2,
	…
}