fixed writing of structures

[veenstrajelmer]

Issue addressed

Fixes #150

Explanation

I noticed an error upon writing the dflowfm_local model so I created as close to a unittest as I can get and fixed the issue. With new pandas versions there are nans instead of None values.

Checklist

• [x] Updated tests or added new tests
• [x] Branch is up to date with main
• [x] Tests & pre-commit hooks pass
• [x] Updated documentation if needed >> not needed, no impact for the user (besides ability to write this model)
• [x] Updated changelog.rst if needed >> not needed

Additional Notes (optional)

We could consider creating fixtures of the two example models since that significantly speeds things up. But I would actually prefer to have a proper unittest instead.

[hboisgon]

Hydromt released new versions of the artifact_data catalog yesterday so I decided to update this here. I also on the way saw that you had some tests thta were commented and I now enabled them :)

[veenstrajelmer]

Thanks a lot @hboisgon for this amazing contribution. I will merge this after all tests pass again and then also update the other PR's so they will also have passing tests.

[sonarcloud[bot]]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud