Support for pws files and layer images

[rudetrooper]

Discussed in #458

^{Originally posted by rudetrooper August 28, 2021}
How should I add the changes I made to support pws files and display layer images back into Mariner?
It would be nice if Mariner could display layer images but I don't know how to adapt my code to add that functionality to Mariner. At the moment I've only written code to display layer images for CTBv1-CTBv3, photon, and the various pws files.
https://github.com/rudetrooper/Octoprint-Chituboard/tree/main/octoprint_chituboard/file_formats

[luizribeiro]

The work involved here would be very similar to this PR, which introduced support for .photon files: #440