🩹 Fix crash when plotting spectral model result

[s-weigand]

This change fixes that high-level plot functions crash if the result data do not have a time axis (e.g. for a spectral model) and should be fully backwards compatible.
This is just a hotfix since it does not implement fully correct behavior for results from a spectral models (e.g. which plot to apply linlog to).
But properly handling non kinetic models will be left for a follow up PR.

Change summary

• 🩹 Fix crash when plotting spectral model result

Checklist

• ✔️ Passing the tests (mandatory for all PR's)

[github-actions]

👈 Launch a binder notebook on branch s-weigand/pyglotaran-extras/fix-spectral-model-plotting-crash

[codecov]

Codecov Report

Patch coverage has no change and project coverage change: +0.08% 🎉

Comparison is base (60b74fe) 44.71% compared to head (f4ea157) 44.80%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #200      +/-   ##
==========================================
+ Coverage   44.71%   44.80%   +0.08%     
==========================================
  Files          27       27              
  Lines        1013     1011       -2     
  Branches      155      155              
==========================================
  Hits          453      453              
+ Misses        552      550       -2     
  Partials        8        8              

Files Changed	Coverage Δ
...glotaran_extras/plotting/plot_coherent_artifact.py	22.91% <0.00%> (ø)
pyglotaran_extras/plotting/plot_data.py	34.04% <0.00%> (ø)
pyglotaran_extras/plotting/plot_doas.py	24.07% <ø> (ø)
pyglotaran_extras/plotting/plot_residual.py	29.03% <0.00%> (ø)
pyglotaran_extras/plotting/plot_svd.py	21.12% <0.00%> (+0.57%)	⬆️
pyglotaran_extras/plotting/utils.py	36.90% <0.00%> (ø)

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[jsnel]

Nothing as permanent as a temporary fix that's also backwards compatible :p

But in this case I'm sure we'll address it in a follow up PR, but good that at least this fixes spectra plotting. Tested against the script fit_simData01.py with show_plot=True here.