Fixed XRSTimeSeries quality flags from breaking parsing of some XRS data.

[alasdairwilson]

PR Description

Closes #6409

Currently #6260 checks for 2 possible netcdf names for the XRS quality flag column 'xrs[a/b]_flags' and '[a/b]_flag' , this stops TimeSeries from loading in some XRS data files due to KeyError when neither of those exist.

This PR adds support for a 3rd flag column name: 'xrs[a/b]_flag' but maybe there is a 4th (or more) out there though

[nabobalis]

That is quite annoying that they vary at least 3 ways.

[alasdairwilson]

I know the stuff has been running for 60 years or something so changes are excused but there is so much stuff like this with GOES which make it a pain.

[hayesla]

I think we should perhaps think about this some more and maybe have specific 1m/ 2s/background timeseries classes or something

[alasdairwilson]

Even within the same data series they are inconsistent with file names/column names/metadata so while it might be an idea, it doesn't make this kind of thing any tidier.

As an aside I have a scraper for 1m data (plus reader for pre 2009 1m data) but its ugly (secondary client rather than using attrs to select series) so haven't tried to put it in sunpy yet.

[dstansby]

Looks 👍 - I don't suppose there are some small files we can add to our test suite to make sure this doesn't break in the future?

[alasdairwilson]

Looks 👍 - I don't suppose there are some small files we can add to our test suite to make sure this doesn't break in the future?

So I made a test file from a 1m avg goes file and added it to the test suite. I am happy with the PR now as long as you lot are.

[lumberbot-app]

Owee, I'm MrMeeseeks, Look at me.

There seem to be a conflict, please backport manually. Here are approximate instructions:

1. Checkout backport branch and update it.

git checkout 4.0
git pull

2. Cherry pick the first parent branch of the this PR on top of the older branch:

git cherry-pick -x -m1 d08c48c32e6ac774c6d7b32242041bd55c6eec9c

3. You will likely have some merge/cherry-pick conflict here, fix them and commit:

git commit -am 'Backport PR #6410: Fixed XRSTimeSeries quality flags from breaking parsing of some XRS data.'

4. Push to a named branch:

git push YOURFORK 4.0:auto-backport-of-pr-6410-on-4.0

5. Create a PR against branch 4.0, I would have named this PR:

"Backport PR #6410 on branch 4.0 (Fixed XRSTimeSeries quality flags from breaking parsing of some XRS data.)"

And apply the correct labels and milestones.

Congratulations — you did some good work! Hopefully your backport PR will be tested by the continuous integration and merged soon!

Remember to remove the Still Needs Manual Backport label once the PR gets merged.

If these instructions are inaccurate, feel free to suggest an improvement.