Fixing C2v, adding stereographic plots for every point group, and making SYmmetry match ITOC standards

[argerlt]

Description of the change

This started as an update to the plot_symmetry_operations example, which has a few errors and also does not match the symbol conventions in the International ables of Crystallography (ITOC).

I decided to procedurally generate plots for all the point groups (most the hard work was already done, thank you @hakonanes for that), and in the process noticed orix.quaternion.symmetry.C2v was inconsistently defined compared to the other groups as well as ITOC. the common convention is to place the main cyclic rotation group around the z-axis.

In hunting that down, I also noticed some of the symmetry group names also did not match the ITOC names, and some other very minor inconsistencies in naming conventions, so I cleaned them up along with some other functions. I also added some descriptions to existing functions to help with clairity.

orix.quaternion.symmetry should be much more closely aligned with ITOC once this is pushed. Additionally, the following picture shows the auto-generatred stereographic plots for every point group

Progress of the PR

• [x] Docstrings for all functions
• [x] Unit tests with pytest for all lines
• [x] Clean code style by running black via pre-commit

Minimal example of the bug fix or new feature

see orix/examples/stereographic_projection/plot_symmetry_operations.py and the plot above.

For reviewers

• [ ] The PR title is short, concise, and will make sense 1 year later.
• [ ] New functions are imported in corresponding __init__.py.
• [ ] New features, API changes, and deprecations are mentioned in the unreleased section in CHANGELOG.rst.
• [ ] Contributor(s) are listed correctly in __credits__ in orix/__init__.py and in .zenodo.json.