fix(gridintersect): gridintersect does not work for rotated vertex grids

[dbrakenhoff]

This PR fixes #2106.

• Gridintersect now correctly picks up the rotated/offset real-world coordinates for vertex grids.
• Added a local kwarg that uses local model coordinates to build intersection grid if set to True.
• Added tests

When looking through the documentation of the Grid objects I came across some entries under Attributes and Methods that do not seem to be used:

• xgrid, ygrid and zgrid are not valid attributes as far as I can tell
• xyzgrid is not an attribute and only available as key in Grid._cache_dict
• the method xyvertices also doesn't exist

I removed them now in this PR, but if this is best fixed/improved in a separate PR, let me know.

[codecov]

Codecov Report

Attention: 4 lines in your changes are missing coverage. Please review.

Comparison is base (626563a) 73.0% compared to head (46cfea7) 73.0%.

Additional details and impacted files

@@            Coverage Diff            @@
##           develop   #2107     +/-   ##
=========================================
- Coverage     73.0%   73.0%   -0.1%     
=========================================
  Files          259     259             
  Lines        59415   59396     -19     
=========================================
- Hits         43401   43386     -15     
+ Misses       16014   16010      -4     

Files	Coverage Δ
flopy/discretization/grid.py	76.0% <ø> (ø)
flopy/utils/gridintersect.py	68.5% <77.7%> (-0.1%)	⬇️

... and 4 files with indirect coverage changes

[wpbonelli]

if I understand #2106 this will change the existing behavior, I wonder if it is safer if local defaults true for now, and switches to false with the next major release?

[dbrakenhoff]

You're right that this will change the default, but only for VertexGrids. The structured grids methods dealt with the rotated offset grids correctly.

So to keep current behavior I can set local to None by default and distinguish between the following routes:

• method="vertex" forces local to True unless explicitly set (with a warning)
• method="structured" defaults to False

In the next major release we can set local=False and remove the warning for method="vertex".

Would that be a good solution?

[wpbonelli]

Since defaulting false makes structured and vertex grids consistent I see your case now to consider it a fix not a breaking change and do it now. And then we don't have to remember to switch with flopy 4