Add chpi to known channel list

[skjerns]

PR Description

cHPI was not in the mapping dictionary, I've added it and also added a test.

resolves #1323

Additionally, I found that there are some other channels that are not known/converted and some channel types that are not known to MNE but are still in the mapping dictionary (can they in practice ever arise if they're not in MNE?)

I think we should be able to get an up to date channel list from this code and could use it in the test. However, the module is private, making it harder to access.

Merge checklist

Maintainer, please confirm the following before merging.
If applicable:

• All comments are resolved
• This is not your own PR
• All CIs are happy
• PR title starts with [MRG]
• whats_new.rst is updated
• New contributors have been added to CITATION.cff
• PR description includes phrase "closes <#issue-number>"

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 97.47%. Comparing base (a0ff786) to head (b332bfc).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1325   +/-   ##
=======================================
  Coverage   97.47%   97.47%           
=======================================
  Files          40       40           
  Lines        8872     8876    +4     
=======================================
+ Hits         8648     8652    +4     
  Misses        224      224           

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[skjerns]

ready for review :)

[sappelhoff]

Thanks!

[sappelhoff]

Could you please add an entry to the changelog? Then we can merge it.

[skjerns]

Done!

edit: Apparently I was already part of the author's list - weird, I never contributed here. Maybe that's from my involvement of MNE?

[sappelhoff]

you DID contribute in 2021! 😄 how the time flies:

• [MRG] fix loading without age information / single-column .tsv #912

[sappelhoff]

Thanks!

[skjerns]

you DID contribute in 2021! 😄 how the time flies:

• [MRG] fix loading without age information / single-column .tsv #912

haha, wow. I never actually used mne-bids after that :D