feat(GWE/SWF): support GWE and SWF models

[wpbonelli]

• add DFN files and (re)generate component classes for new GWE and SWF models
• includes all files touched by flopy.mf6.utils.generate_classes, many of which just have updated timestamps — could remove files not related to GWE or SWF from this PR, but seems preferable to either keep timestamps consistent for auto-generated files or remove the timestamps to avoid bloated changesets, and just use git to track edit history
• notebook CI tests are expected to fail until executable distribution is re-released with accurate code.json, for now get-modflow doesn't extract double-precision programs

[codecov]

Codecov Report

Attention: 444 lines in your changes are missing coverage. Please review.

Comparison is base (626563a) 73.0% compared to head (67f2e72) 72.7%.

Additional details and impacted files

@@            Coverage Diff            @@
##           develop   #2109     +/-   ##
=========================================
- Coverage     73.0%   72.7%   -0.3%     
=========================================
  Files          259     293     +34     
  Lines        59415   60733   +1318     
=========================================
+ Hits         43401   44189    +788     
- Misses       16014   16544    +530     

Files	Coverage Δ
flopy/mf6/modflow/__init__.py	100.0% <100.0%> (ø)
flopy/mf6/modflow/mfems.py	72.7% <ø> (ø)
flopy/mf6/modflow/mfgnc.py	90.9% <ø> (ø)
flopy/mf6/modflow/mfgwf.py	100.0% <ø> (ø)
flopy/mf6/modflow/mfgwfapi.py	69.6% <ø> (ø)
flopy/mf6/modflow/mfgwfbuy.py	74.1% <ø> (ø)
flopy/mf6/modflow/mfgwfchd.py	100.0% <ø> (ø)
flopy/mf6/modflow/mfgwfcsub.py	67.5% <ø> (ø)
flopy/mf6/modflow/mfgwfdis.py	100.0% <ø> (ø)
flopy/mf6/modflow/mfgwfdisu.py	100.0% <ø> (ø)
... and 96 more

... and 17 files with indirect coverage changes

[langevin-usgs]

I wonder if we should remove the date/time stamp, as you mentioned. This would reduce all the chatter. Or maybe we could use the flopy version number instead?

I don't feel strongly about adding the gwe/swf/prt dfns and related classes right away as these models are not really supported yet, but if having them included in flopy simplifies CI or is beneficial in other ways then let's get them in.

[wpbonelli]

On second thought I think this may be premature- may make more sense to wait until just before the new models are released, since dfns may change in the meantime. I will close for now if you agree.

I wonder if we should remove the date/time stamp, as you mentioned. This would reduce all the chatter. Or maybe we could use the flopy version number instead?

the version number makes sense to me. that would (roughly*) identify the createpackages.py that generated files, may come in handy for debugging

*if we ever move to something like setuptools_scm or versioneer the version string could even include the commit hash