Add a test to ensure seviri hrv has priority over vis008 when requesting 0.8µm

[mraspaud]

This PR just adds a test to settle an unclear behaviour.

• Tests added
• Fully documented

[codecov]

Codecov Report

Merging #1720 (351e2c8) into main (cf546ba) will increase coverage by 0.02%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main    #1720      +/-   ##
==========================================
+ Coverage   92.56%   92.58%   +0.02%     
==========================================
  Files         258      258              
  Lines       38338    38343       +5     
==========================================
+ Hits        35487    35501      +14     
+ Misses       2851     2842       -9     

Flag	Coverage Δ
behaviourtests	4.83% <0.00%> (+<0.01%)	⬆️
unittests	93.13% <100.00%> (+0.02%)	⬆️

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Impacted Files	Coverage Δ
satpy/tests/test_dataset.py	100.00% <100.00%> (ø)
satpy/dataset/dataid.py	94.27% <0.00%> (+0.22%)	⬆️
satpy/tests/reader_tests/test_vii_base_nc.py	98.78% <0.00%> (+1.21%)	⬆️
satpy/tests/reader_tests/test_nwcsaf_msg.py	98.31% <0.00%> (+1.68%)	⬆️
satpy/tests/reader_tests/test_vii_l1b_nc.py	100.00% <0.00%> (+2.81%)	⬆️
satpy/tests/reader_tests/test_vii_l2_nc.py	100.00% <0.00%> (+6.06%)	⬆️

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[coveralls]

Coverage increased (+0.004%) to 93.076% when pulling 351e2c8 on mraspaud:fix-seviri-vis008-vs-hrv into cf546ba on pytroll:main.

[mraspaud]

@djhoese any comment on this?

[djhoese]

I'm confused. Based on the slack conversation don't we want 0.8 to give VIS008 back? Or is the current behavior actually desired?

[mraspaud]

I think the approach is consistent, in that higher resolution is said to be preferred. I was confused earlier because the previous behaviour preferred nearer center wavelength.

But in the end, I think I agree with #1721 , but for now this is good enough.