GuideCamera::Capture CaptureParams argument

[agalasso]

GuideCamera::Capture CaptureParams argument

Update GuideCamera::Capture method replacing individual capture parameter arguments
with a struct wrapping all the capture parameters.

This will make it easier to transform the arguments for software binning #738.

No functional changes in this PR - just the arguments structure refactor.

[bwdev01]

I'm missing something here. What is the benefit of pushing all these additional properties - gain, binning, bpp, etc - into the Capture() interface. Those things are already known to the underlying function because they are just properties of the camera. The new struct just looks to me like it has a bunch of tramp properties that, as a caller of Capture, I don't need to know about.

[agalasso]

This change accomplishes two things:

1. primarily: this makes it easier to transform the capture parameters for software binning. The capture params can be modified and passed along (this happens in the final pr of the series.) In that case we start with software-binned coordinates, transform to non-software binned camera coordinates in the call to the camera Capture instance method.
2. secondary benefit: This will allow a cleaner implementation of the capture_single_frame server API which currently has to modify GuideCamera settings, call Capture, then restore the camera settings afterwards. The new implementation (not yet implemented) can leave GuideCamera settings as-is, and only pass along customized CaptureParams. Changing and restoring the camera settings is not ideal since the code has to make sure the settings get set back under all circumstances, and must ensure they do not change after capture_single_frame is called and before the frame capture completes.

[bwdev01]

Ok