Add subcommand `gribmagic smith regrid`

[amotl]

Hi there,

this patch adds the gribmagic.smith.regrid module and the accompanying command gribmagic smith regrid. It has code to transform DWD ICON's icosahedral-gridded files into regular grids in long1 format.

With kind regards, Andreas.

[codecov[bot]]

Codecov Report

Merging #17 (08b7ff8) into main (1b64033) will decrease coverage by 0.46%. The diff coverage is 88.11%.

@@            Coverage Diff             @@
##             main      #17      +/-   ##
==========================================
- Coverage   91.32%   90.85%   -0.47%     
==========================================
  Files          20       24       +4     
  Lines         795      995     +200     
  Branches       79      108      +29     
==========================================
+ Hits          726      904     +178     
- Misses         54       66      +12     
- Partials       15       25      +10     

Flag	Coverage Δ
unittests	90.85% <88.11%> (-0.47%)	:arrow_down:

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

Impacted Files	Coverage Δ
gribmagic/installer.py	44.44% <0.00%> (-18.72%)	:arrow_down:
gribmagic/smith/bbox.py	75.75% <66.66%> (-3.46%)	:arrow_down:
gribmagic/smith/regrid/engine.py	87.65% <87.65%> (ø)
gribmagic/smith/util.py	97.36% <97.36%> (ø)
gribmagic/commands.py	100.00% <100.00%> (ø)
gribmagic/smith/regrid/cli.py	100.00% <100.00%> (ø)
gribmagic/smith/regrid/model.py	100.00% <100.00%> (ø)
gribmagic/util.py	100.00% <100.00%> (ø)

---

Continue to review full report at Codecov.

Legend - Click here to learn more Δ = absolute <relative> (impact), ø = not affected, ? = missing data Powered by Codecov. Last update 1b64033...08b7ff8. Read the comment docs.