PR623 Add "Phase.plot_unit_cell" function

[argerlt]

Description of the change

As part of updating the examples, I wanted to be able to plot a unit cell. It ended up being nicer to just make it a class feature as opposed to a function in an example. This does that, and replaces a large chunck of crystal_map.ipynb with examples.

For reference, here are similar functions in other packages
py4dstem kinematical example notebook
The atomic models tutorial from abTEM
MTEX

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

import diffpy.structure as dps
import orix.crystal_map as ocm

atoms = [
    dps.Atom("Al",[1/3,2/3,0.815]),
         dps.Atom("O",[0.361,1/3,0.583]),
         ]
lattice = dps.Lattice(0.481, 0.481, 1.391, 90, 90, 120)
structure = dps.Structure(atoms=atoms, lattice=lattice)
Al2O3_phase = ocm.Phase(name = "Alumina",
    space_group = 167,
    structure = structure,
    color = 'red',
).expand_asymmetric_unit()

unit_cell_figure = Al2O3_phase.plot_unit_cell(return_figure=True)
unit_cell_figure.suptitle(r"$Al_2O_3$ unit cell")

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.

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[argerlt]

pre-commit.ci autofix

[argerlt]

pre-commit.ci autofix

[argerlt]

@hakonanes, it looks like psf/black and pre-commit are disagreeing with each other on how to format "S2_sampling.py".

My thought is to just remove the psf/black check from workflows. we can do it in the hotfix 0.14.2 hotfix if you agree.

[argerlt]

pre-commit.ci autofix