Complete EDAX symmetry aliases

[hakonanes]

Description of the change

Fixes #534.

Progress of the PR

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

Minimal example of the bug fix or new feature

>>> from orix import io
>>> xmap = io.load("Ti_single_crystal_scan.ang")
[/Users/hakon/kode/personal/orix/orix/io/plugins/ang.py:285](https://file+.vscode-resource.vscode-cdn.net/Users/hakon/kode/personal/orix/orix/io/plugins/ang.py:285): UserWarning: Number of columns, 13, in the file is not equal to the expected number of columns, [14, 10], for the 
assumed vendor 'tsl'. Will therefore assume the following columns: euler1, euler2, euler3, x, y, unknown1, unknown2, phase_id, unknown3, unknown4, etc.
  warnings.warn(
>>> print(xmap)
Phase    Orientations  Name  Space group  Point group  Proper point group     Color
    0  10324 (100.0%)    Ti         None          622                 622  tab:blue
Properties: unknown1, unknown2, unknown3, unknown4, unknown5, unknown6, unknown7
Scan unit: um

(Need to look at the header.)

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.

[CSSFrancis]

This looks good to me! Simple enough change and tested.

[hakonanes]

Thanks! I'll prepare a patch release for the new year.