Stereogram plot

[Souza-junior]

Relevant issues/PRs:

[leouieda]

@Souza-junior @YagoMCastro this would be much better as a matplotlib projection. That way matplotlib has tools to help draw grids, set ticks, etc. See https://matplotlib.org/stable/api/projections_api.html

[leouieda]

Tests are failing because we need add matplotlib as a run-time dependency to pyproject.toml. The minimum required version should be a minor release from at least 2 years ago. Check the matplotlib changelog to see which one.

[leouieda]

For testing, use the pytest-mpl plugin. It needs to be added to the environment.yml and env/requirements-test.txt files.

[leouieda]

The matplotlib projection stuff could be a follow up PR later. @YagoMCastro could you open an issue for that, please?

[YagoMCastro]

Thank you for the great work on this. I noticed that there is a class that currently contain only a single function. In these cases, it might be more efficient to substitute the class with just a standalone function. This could help simplify the code and improve readability. What do you think?