test: fast hardware acqui testing via embedded

[ianohara]

This adds a (temporary) command on the embedded side that lets us kick of trigger sequences, and an accompanying script to use this. Once you flash this new firmware, an example invocation of the script is:

python tools/hardware_acquisition_capture_test.py --camera toupcam --exposure 1 --frame_count 10 --max_runtime 5 --verbose --batch_mode

If you leave off --batch_mode, the standard one-at-a-time triggering will be used.

Tested by: Tested on a system with a toupcam and cephla stage. I hooked up an oscilloscope to the trigger line to verify the high/low intervals and counts.

[ianohara]

Example usage: python tools/hardware_acuisition_capture_test.py --camera toupcam --exposure 1 --frame_count 10 --max_runtime 5 --verbose --batch_mode