[IN REVIEW] Add vanishing strain wrapper (for plane strain)

[henrij22]

This adds a Material Wrapper for vanishing strain, mostly used by plane strain, this should work similar to planeStress from the VanishingStress implementation, but without using a nonlinear solver and directly setting the fixed indices of the strains to zero Original implementation by @tarun-mitruka

Ive tested the plane Strain case against my own implementation, but I havn't wrote a formal test with some actual values. It passes the testmaterials test and an additional one where i compare plane strain and plane stress for $\nu = 0$ where the two 2d models should match.

TODO

• [ ] Think about constructors of materials. Currently the python materials takes $\lambda$ and $\nu$, where as the C++ Materials take $\Lambda$ and $\mu$ (python done)
• [ ] Planar materials should return planar stress tensor (issue #254), voigt is already correct
• [ ] It should be possible to pass planar tensors into the reduced materials, voigt is already correctly working, (Hint: modify maybeEnlarge Function)

MAYBE TODO

• [ ] Check if the entries {0, 1, 5} matter if the grid is defined in the XZ-plane or in the YZ-plane? - may be not if isotropy is assumed
• [ ] May be check if the material tangent and the stress measure is correct using autodiff on the storedEnergyImpl? But this is a bit heavy and can be moved to a separate PR?

OTHER PR

• [ ] Check plane strain case for nonlinearelastic.hh (this can be done in https://github.com/ikarus-project/ikarus/issues/285)

DONE

• [x] Enhance Python Bindings, e.g. use python enums for strain tags
• [ ] Pyhton material constructor now takes arbitrary arguments
• [x] Discuss and maybe modify the constructor of LinearElastic such that it is similar to NonlinearElastic - This is necessary to make LinearElastic work for both plane strain and plane stress case. Consequently remove planeStressLinearElasticMaterialTangent and linearElasticMaterialTangent3D from physicshelper.hh.
• [x] Add generalized version called VanishingStrain and let planeStrain be a special case
• [x] Check quantities using the strain measure in matrix notation - stress, material tangent, and energy
• [x] Check quantities using the strain measure in vector (Voigt) notation - stress, material tangent, and energy
• [x] Check if plane stress case and plane strain case provide the same results for both St. Venant Kirchhoff and Neo-Hookean Material model when the Poisson's ratio is zero
• [x] If linearElasticMaterialTangent3D is removed, test if the material tangent is still correct for the 3D case (perhaps this is checked indirectly using the tests for result functions?)
• [x] Also add similar tests in Python
• [x] Check if VanishingStrain works correctly with free and fixed indices different from plane strain case
• [x] Check plane strain case for linearelastic.hh

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 84.00000% with 8 lines in your changes missing coverage. Please review.

Project coverage is 48.11%. Comparing base (d05187e) to head (5c350e6).

Files with missing lines	Patch %	Lines
...iteelements/mechanics/materials/vanishingstress.hh	45.45%	6 Missing :warning:
...teelements/mechanics/materials/linearelasticity.hh	66.66%	1 Missing :warning:
...rus/finiteelements/mechanics/materials/neohooke.hh	75.00%	1 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #317 +/- ## =========================================== - Coverage 80.96% 48.11% -32.86% =========================================== Files 68 69 +1 Lines 2291 2336 +45 =========================================== - Hits 1855 1124 -731 - Misses 436 1212 +776 ``` | [Flag](https://app.codecov.io/gh/ikarus-project/ikarus/pull/317/flags?src=pr&el=flags&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=ikarus-project) | Coverage Δ | | |---|---|---| | [tests](https://app.codecov.io/gh/ikarus-project/ikarus/pull/317/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=ikarus-project) | `48.11% <84.00%> (-32.86%)` | :arrow_down: | Flags with carried forward coverage won't be shown. [Click here](https://docs.codecov.io/docs/carryforward-flags?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=ikarus-project#carryforward-flags-in-the-pull-request-comment) to find out more.

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[henrij22]

@rath3t There are some open points to discuss, but for a first review this is ready from my side.