Build a Pure python wheel for pyxem

[CSSFrancis]

Proposal: Build a Pure python wheel for pyxem

We should be able to build a pure python wheel for pyxem so it can be used inside of a Jupyter-lite instance or a pyodide application. While performance wise this is not a great option there are many interesting and cool things being done in this space.

1. The most obvious is that we could have our tutorials run in Jupyter-lite within the browser.
2. This opens up some possibilities to making a pyxem web application if you can access a local file system or connect to a server
3. It also provides some interesting possibilities with things like Jupyter-book, and Jupyter-deck where you can create interactive publications.
4. Dask is experimenting with connecting to remote clusters using jupyter-lite. This could be another interesting pathway for connecting to remote resources.

Describe the solution you'd like

There are quite a few barriers to this:

• Hyperspy
• rosettasciio
• Remove dependency on pyfai (or make it optional) Pyfai is kind of large, adds a lot of dependancies and we should probably rewrite some things with electron diffraction in mind.
• orix (dependance on numba and hpy5)
• diffsims (dependance on diffpy.Strucuture which needs a pure python wheel)
• numba (make optional for extra speed)