Add some global EPSG 4326 gridded lat/lon areas.

[simonrp84]

This PR adds some global EPSG:4326 area definitions for lat/lon grids at the following resolutions:

• 0.01 degree
• 0.05 degree
• 0.25 degree
• 0.50 degree
• 1.00 degree

I chose these resolutions as they're ones that I've seen in common use and are hence those I think will be most useful across various use cases.

[simonrp84]

pre-commit.ci autofix

[mraspaud]

I'm only now realizing that this can be achieved easily with:

In [4]: AreaDefinition.from_epsg(4326, 0.1)
Out[4]: 
Area ID: WGS 84
Description: WGS 84
Projection: {'datum': 'WGS84', 'no_defs': 'None', 'proj': 'longlat', 'type': 'crs'}
Number of columns: 3600
Number of rows: 1800
Area extent: (-180.0, -90.0, 180.0, 90.0)

etc...

[codecov]

Codecov Report

Merging #2600 (81af838) into main (056a3a9) will decrease coverage by 0.03%.
Report is 109 commits behind head on main.
The diff coverage is 95.87%.

@@            Coverage Diff             @@
##             main    #2600      +/-   ##
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- Coverage   94.94%   94.92%   -0.03%     
==========================================
  Files         354      354              
  Lines       51474    51474              
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- Hits        48873    48862      -11     
- Misses       2601     2612      +11     

Flag	Coverage Δ
behaviourtests	4.26% <3.09%> (-0.01%)	⬇️
unittests	95.54% <98.08%> (-0.03%)	⬇️

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

Files	Coverage Δ
satpy/_compat.py	57.14% <100.00%> (ø)
satpy/_config.py	96.59% <100.00%> (ø)
satpy/composites/spectral.py	100.00% <100.00%> (ø)
satpy/modifiers/__init__.py	100.00% <100.00%> (ø)
satpy/modifiers/angles.py	99.21% <100.00%> (ø)
satpy/modifiers/geometry.py	90.32% <100.00%> (ø)
satpy/multiscene/__init__.py	100.00% <100.00%> (ø)
satpy/multiscene/_blend_funcs.py	100.00% <100.00%> (ø)
satpy/multiscene/_multiscene.py	92.81% <ø> (ø)
satpy/readers/aapp_mhs_amsub_l1c.py	95.94% <100.00%> (ø)
... and 21 more

... and 6 files with indirect coverage changes

[djhoese]

I'd like to point out that this could reveal some fun bugs in satpy and pyresample as technically speaking EPSG:4326 has (lat, lon) ordered axes rather than our usual (lon-x, lat-y) ordering. Pyresample is pretty good about asking pyproj to force x/y order, but I'm sure there are some spots that aren't doing it.

Additionally, GDAL recommends not using 4326: https://gdal.org/user/coordinate_epoch.html#dynamic-crs-and-coordinate-epoch

The generic EPSG:4326 WGS 84 CRS is also considered dynamic, although it is not recommended to use it due to being based on a datum ensemble whose positional accuracy is 2 meters, but prefer one of its realizations, such as WGS 84 (G1762)

[mraspaud]

LGTM