app_full.py is compatible with monochrome sensors. Fixes #1380

[fiepfiep]

Fixes #1380
add a check for monochrome sensors before accessing controls such as AWB, saturation.
@davidplowman

[davidplowman]

Thanks for the PR. Actually we've just added a mono sensor into our "fleet" of test devices which is why there are some failures, so we'll get those cleaned up first.

On reflection, I might add a picam2.is_mono() function, which might make this a bit neater. I'll also replace 5 by libcamera.properties.draft.ColorFilterArrangementEnum.MONO which, although a bit of a mouthful, doesn't have that fragility problem we mentioned elsewhere. Thanks!

[davidplowman]

We've gone through all the other test failures for mono sensors and fixed them up, and taken care of this one too. That's all been merged onto our next branch now so will be in the next release, along with a picam2.is_mono property. I think that takes care of everything so I'll close this one now, but thanks for bringing it all to our attention. With a mono sensor in our test farm too now, hopefully we'll get less of this kind of thing in future!