Port mitiff writer to use pillow

[TAlonglong]

• Closes #xxxx
• Tests added
• Fully documented
• Add your name to AUTHORS.md if not there already

[TAlonglong]

pre-commit.ci autofix

[codecov]

Codecov Report

Merging #2315 (d8fd2a2) into main (f7e056d) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##             main    #2315   +/-   ##
=======================================
  Coverage   94.36%   94.37%           
=======================================
  Files         310      310           
  Lines       46641    46665   +24     
=======================================
+ Hits        44014    44040   +26     
+ Misses       2627     2625    -2     

Flag	Coverage Δ
behaviourtests	4.59% <0.00%> (-0.01%)	⬇️
unittests	95.01% <100.00%> (+<0.01%)	⬆️

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Impacted Files	Coverage Δ
satpy/tests/writer_tests/test_mitiff.py	99.19% <100.00%> (+0.02%)	⬆️
satpy/writers/mitiff.py	93.33% <100.00%> (+0.88%)	⬆️
satpy/readers/ahi_hsd.py	97.50% <0.00%> (-0.36%)	⬇️
satpy/tests/reader_tests/test_seviri_l1b_nc.py	100.00% <0.00%> (ø)

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[coveralls]

Coverage increased (+0.007%) to 94.964% when pulling d8fd2a2 on TAlonglong:port-mitiff-writer-to-use-pillow into f7e056d on pytroll:main.

[TAlonglong]

pre-commit.ci autofix

[mraspaud]

Great work with the fast conversion to PIL, thanks a lot! I don't have anything to say on the logic, looks good. Some style comments inline

[TAlonglong]

pre-commit.ci autofix

[TAlonglong]

Thanks @mraspaud, I did some updates to reduce duplicated code.

[mraspaud]

LGTM!