add callback function argument to fit function for progress output

[mitch-galea]

When processing larger pointclouds, the processing time can take a while, especially with a higher max_iteration value. It would be helpful to have an argument for a progress callback function. I have seen a similar design pattern with a photogrammetry software Metashape (see documentation here https://www.agisoft.com/pdf/metashape_python_api_1_8_0.pdf)