Issue #974 distribute drain conductance

[JoerivanEngelen]

Fixes #974

Description

This PR adds the options to distribute drain conductances.

• Adds by_crosscut_thickness, by_crosscut_transmissivity, by_corrected_transmissivity options to Drain package
• Make boundary conditions top and bottom arguments optional methods
• Change order of arguments conductance distribution functions

Checklist

• Links to correct issue
• Update changelog, if changes affect users
• PR title starts with Issue #nr, e.g. Issue #737
• Unit tests were added
• If feature added: Added/extended example

[luitjansl]

1 comment ( but approved in advance)

[luitjansl]

you only compare "actual" and "expected" in the first cell. So it would make the tests more strict if arrays like "bottom" and "elevation" have a different value in the first cell than in the rest of the array. Otherwise the tests would still pass even if something went wrong in the indexing.

[JoerivanEngelen]

By doing this, we would mainly test if the testing utility function take_first_cell_in_xy_plane does what it's supposed to do. I think this adds quite some complexity to the test cases for relatively little gains. I think it is better to allocate our constrained resources to fixing other issues.