[WIP] Add tosi rathmann benchmark

[Theo-Geo]

I added a benchmark based on Tosi et.al. 2015 and Rathmann et.al. 2024 . It uses the CPO_AV plugin as a base model and the results can be compared to Rathmann et.al. 2024 (once the results are consistent).

For this i also had to correct remaining inconsistencies in the CPO_AV material model and allow cpo calculations in 2d by removing an assert.

at the moment the things which are missing are:

• fixing the interpolation of rotation from particles to the grid
• adding a second figure for the velocity and temperature evolution to compare the cases
  • adding a python file to generate it
• adding the test to the tester and giving it an ideal output
• make indent

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• I have followed the instructions for indenting my code.
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  • Significant parts of this PR were written by AI (please add a sentence below).
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I did not use AI to generate any of the parts of the benchmark.

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