Convert AHI HSD dask chunking to be based on band resolution

[djhoese]

As discussed in #2562, performance (memory usage for sure) is better when chunking is done based on resolution. Especially when native resampling is done. This means the 500m band's chunks are twice the size of the 1km band's chunks and 4 times the size of the 2km band's chunks. This should mean dask doesn't have to do any rechunking.

This PR is a continuation of #2052 and should be rebased/remerged after that is merged first. This PR also includes a fix for sunz correction where the dtype for 32-bit floats was being bumped up to 64-bit floats inside dask computations causing more memory usage than we thought.

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

[djhoese]

Oh I still need to add tests for the reader chunking and dtype fixes there.

[codecov]

Codecov Report

Merging #2584 (ec20ba9) into main (8d68425) will increase coverage by 0.00%.
Report is 23 commits behind head on main.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##             main    #2584   +/-   ##
=======================================
  Coverage   94.92%   94.92%           
=======================================
  Files         350      350           
  Lines       51085    51098   +13     
=======================================
+ Hits        48491    48504   +13     
  Misses       2594     2594           

Flag	Coverage Δ
behaviourtests	4.28% <0.00%> (-0.01%)	⬇️
unittests	95.54% <100.00%> (+<0.01%)	⬆️

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

Files	Coverage Δ
satpy/modifiers/angles.py	99.17% <100.00%> (ø)
satpy/readers/ahi_hsd.py	99.29% <100.00%> (ø)
satpy/tests/reader_tests/test_ahi_hsd.py	99.68% <100.00%> (+<0.01%)	⬆️
satpy/tests/test_modifiers.py	100.00% <100.00%> (ø)

[coveralls]

Pull Request Test Coverage Report for Build 6425912482

• 31 of 31 (100.0%) changed or added relevant lines in 4 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.001%) to 95.495%

---

Totals
Change from base Build 6424552767:	0.001%
Covered Lines:	48627
Relevant Lines:	50921

---

💛 - Coveralls

[mraspaud]

Lgtm! Feel free to merge when the rebating is done and the tests pass.

[djhoese]

Reran my profiling and got the same results as before all this rebasing and refactoring so I think we're good here.