Chamber: add feature to set material model in input file

[KatrinKoesler]

Problem

Different material models for the spherical chamber might be useful for different simulation purposes. Currently, only one material model is implemented and if a new material is being implemented, a new block has to be implemented.

Solution

It would be useful to be able to select the appropriate material model in the input file while still using the same chamber block. This can be done by reading a string from the input file and having different materials implemented within the chamber block that are selected based on this string.

Additional context

No response

Code of Conduct

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[mrp089]

This could be done by having a sphere base class that has pure virtual functions to get the derivatives of the strain energy function with respect to the invariants, which are implemented in the derived classes for different material models. See ClosedLoopCoronaryBC as an example of that structure. This would be cleaner than having a bunch of switch case statements.