General purpose camera pipeline in checkbox_support (New)

[tomli380576]

Description

(This PR is the 1st part of the previously implemented automatic gstreamer pipeline that was too big)

This PR adds a general purpose pipeline runner run_pipeline in checkbox_support and an example driver code take_photo that takes a photo using this runner

Resolved issues

#1676 <-- was too big for review

Documentation

I drafted a short design doc to explain some of the weirdness/quirks in the code that might not be fully explained by the comments. Hopefully this helps with the review :)

Tests

Unit tests. Also tested on real devices with USB cameras using the following driver code

if __name__ == "__main__":
    Gst.init([])
    # replace the element with what's available on your system
    elem = Gst.parse_launch("pipewiresrc target-object=47")
    assert type(elem) is Gst.Element
    take_photo(elem, file_path=Path("/tmp/photo.jpg"), delay_seconds=3)

Intel MIPI are expected to fail for now since they are only accessible with v4l2src, which isn't exposed in DeviceMonitor.

This also plays well with checkbox timeout:

# normal termination
timeout(10)(take_photo)(elem, file_path=Path("/tmp/photo.jpg"), delay_seconds=3)
# force stop
timeout(3)(take_photo)(elem, file_path=Path("/tmp/photo.jpg"), delay_seconds=10)