Create healthcheck script

[HaythamB]

Develop a small script to test all the functions usually used by openCV, numpy, DuetWebAPI, etc. on a test image and printer.

This "unit test" script would help troubleshoot exceptions and errors that are triggered by 3rd party libraries on the different platforms TAMV is deployed on.

[HaythamB]

functions that sometimes cause issues:

adjust_gamma (Sindarius on discord most likely had this issue, along with a few others) pic