fix serializability of geometry filters

[tyrasd]

Description

Fixes a serializability issue involving the geometry based filters (length: and area:).

This currently causes ohsome API queries to fail if they use these filters: example

Checklist

• My code follows the code-style rules, and I have checked on the static analyses and benchmark (if applicable) results
• I have commented my code
• I have written javadoc (required for public classes and methods)
• I have added sufficient unit tests
• I have made corresponding changes to the documentation
• I have updated the CHANGELOG.md
• I have adjusted the examples or created an issue in the corresponding repository
• I have adjusted the benchmark or created an issue in the corresponding repository

[rtroilo]

I think we should add a test, which could show us if there is a problem with serializability in our code.
Do we have a test that is capable to do so and or how much would be the effort to write such a test?

[tyrasd]

Do we have a test that is capable to do so

not at the moment

and or how much would be the effort to write such a test?

not sure how one would approach it. any suggestions?