Consider re-integrating PyARPES

[kmnhan]

PyARPES seems to be unmaintained: chstan/arpes#23
But has a maintained fork! chstan/arpes#23 (comment)

Although we moved away from PyARPES functionality and are happy, maybe we could consider re-adding compatibility layers since they have many more data plugins...

Options:

• Discard our data model, roll back to PyARPES conventions
  • Pros: we get access to data loaded by PyARPES data loaders!
  • Cons: I personally dislike a lot of things about their data convention like angle notation and attribute mangling, our momentum conversion will need major fixes
• Write a conversion function that transforms PyARPES data format to match ours
  • This should be easy since PyARPES format is very constrained
  • However the other way around will be quite hard
  • And duplicated loader functionality is chaos
• Write a compatibility layer that subclasses a PyARPES loader and BaseLoader (multiple inheritance)
  • Use PyARPES loaders with our syntax!
  • Is this even possible?
• Ignore PyARPES and move on
  • The easiest way
  • However majority of attempts to analyze ARPES data with python are concentrated in PyARPES, could it become standard in the future?
  • We have to implement more data loaders for this to not be a problem