Add tests for XTCE packet parsing

[greglucas]

Summary

There are currently no tests for the XTCE converter content. We should add some tests that mock up a spreadsheet and convert it to an XTCE file with the expected content.

Similar to the metadata_generation tools where we are mocking up spreadsheet tabs already: https://github.com/IMAP-Science-Operations-Center/imap_processing/blob/dev/tools/metadata_generation/tests/test_metadata_generation.py

Requirements

The more specific the better.

• Mock up a spreadsheet with a few packets and tabs (don't add an Excel sheet to the repo)
• Get full coverage for the XTCE converter class

Related tickets

No response

[bourque]

I think this could be a good student task, so I marked it as such

[greglucas]

Apparently we already had this in the test suite, so I'm going to close this issue as already completed. Sorry for the indirection here! See: #783 for a discussion of the updates to dynamically generate the file instead of using the manually saved version.