Main changes of this PR

This PR adds simple exporter tests for scalar, vectorial and missing data.

Motivation and additional information

This would have prevented #2131

Author's checklist

• I used the pre-commit hook to prevent dirty commits and used pre-commit run --all to format old commits.
• I added a changelog file with make changelog if there are user-observable changes since the last release.
• I added a test to cover the proposed changes in our test suite.
• For breaking changes: I documented the changes in the appropriate porting guide.
• I stuck to C++17 features.
• I stuck to CMake version 3.22.1.
• I squashed / am about to squash all commits that should be seen as one.