Switch sand silt parameters

[anne-glerum]

In line with the updated documentation of FastScape (https://fastscape.org/fastscapelib-fortran/#_fastscape_set_marine_parameters, fastscape-lem/fastscapelib-fortran#54), this PR switches the order of sand and silt parameters when setting the marine parameters in FastScape.

It also renames one parameter to be consistent with the FastScape documentation. This is not backwards compatible.

For all pull requests:

• I have followed the instructions for indenting my code.

For new features/models or changes of existing features:

• I have tested my new feature locally to ensure it is correct.
• I have created a testcase for the new feature/benchmark in the tests/ directory.
• I have added a changelog entry in the doc/modules/changes directory that will inform other users of my change.

[gassmoeller]

Ok, we should certainly use the correct order. But just for clarification: Does this mean we were using the wrong order before? Or is this something that changed between Fastscape versions? In this case can we detect the fastscape version we use and adopt the correct order for each? If there are different ways to call this function in different versions we should be either compatible with both, or not allow to use the version not compatible with our call.

[anne-glerum]

Yes, fastscape.cc had the wrong order before.

FastScape itself didn't change, only its documentation. It documented the wrong order, and therefore the ASPECT FastScape interface also used the wrong order.

At least in our section, no one but me has been using two distinct diffusion coefficents for sand and silt. When they are the same, the order doesn't matter.

Shall I add a change log?

[gassmoeller]

Yes, please add a changelog that the order was wrong before. Just so that users now they should use the new version.

[gassmoeller]

Oh and could you rebase the PR as well? The failing tester should be fixed on the main branch, but I would like to see the confirmation.

[anne-glerum]

/rebuild

[gassmoeller]

/rebuild