Fci/l2/amv/reader

[YouvaEUMex]

This PR add a reader for the FCI L2 AMV.
Since the AMV products are NetCDF files that only use 1 dimension (number_of_winds) to define all the variables.
It need a dedicated File Handler to avoid adding exception handler for non-array stuff like x and y.
This File handler inherit FciL2CommonFunctions and only modify a couple of methods including the get_dataset.
It is rather simple and does not process the data.
There is no Area definition since the product does not contain any.
Only the lat,lon needs to be used to project and display the AMV on a map.

• Tests added
• Fully documented(see EUM PUG?)

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (fbe017c) 95.31% compared to head (be666eb) 95.35%.
Report is 34 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2683      +/-   ##
==========================================
+ Coverage   95.31%   95.35%   +0.03%     
==========================================
  Files         371      371              
  Lines       52435    52464      +29     
==========================================
+ Hits        49980    50028      +48     
+ Misses       2455     2436      -19     

Flag	Coverage Δ
behaviourtests	4.15% <0.00%> (-0.01%)	⬇️
unittests	95.97% <100.00%> (+0.03%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

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

[coveralls]

Pull Request Test Coverage Report for Build 7210821644

Warning: This coverage report may be inaccurate.

We've detected an issue with your CI configuration that might affect the accuracy of this pull request's coverage report.
To ensure accuracy in future PRs, please see these guidelines.
A quick fix for this PR: rebase it; your next report should be accurate.

• 65 of 65 (100.0%) changed or added relevant lines in 2 files are covered.
• 49 unchanged lines in 3 files lost coverage.
• Overall coverage increased (+0.04%) to 95.921%

---

Files with Coverage Reduction	New Missed Lines	%
satpy/tests/test_resample.py	2	99.57%
satpy/composites/init.py	4	93.07%
satpy/resample.py	43	88.74%

Totals
Change from base Build 7180375207:	0.04%
Covered Lines:	50154
Relevant Lines:	52287

---

💛 - Coveralls

[mraspaud]

Very nice PR, thanks for putting it up! Some comments and questions inline.

[mraspaud]

LGTM!