Piave test add rainfall

Issue addressed

Fixes #177

Explanation

The last step in syncing the models in the examples and the tests/data folders. To do this, I have added rainfall to the piave model in tests and updated the expected output model accordingly. I have also renamed the piave build yml to contain "piave", just because I found it confusing it did not before.

As a last step, I wanted to remove the redundant yml files in tests/data and instead use the yml files from examples in the tests. This to avoid we have to keep syncing them upon every change. Makes more sense to me. However, I noticed that the paths in test_data.yml are in fact relative to the build yml and not relevant to the test_data.yml, so this caused the build of the local model to fail. I could fix this by moving all example build yml's and the local test data to examples/data (then the build and datacatalog yml's are in the same folder), which kind of makes sense. But I wanted to discuss this first. At the moment I think this PR is also an improvement since the build yml's are now at least completely aligned, some filenames are now more clear (at least to me) and I also removed unused build files.

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 relevant
[x] Updated changelog.rst if needed >> not relevant

Deltares / hydromt_delft3dfm