Mechanical material modeling layer

[termi-official]

Inspired by https://github.com/kimauth/MaterialModels.jl we should add a high level interface for the solid mechanical elements containing

• A stress measure type, mostly for post-processing
• A strain measure type identification struct (e.g. DeformationGradientMeasure, LeftCauchyGreenMeasure)
• A container for different strain quantities (e.g. deformation gradient, material velocity, higher order terms, ...)
• Some ALE connector type
• Material state containers to simplify dispatching the internal solvers
• Transformation and chain-rule functions between the different systems

The current interface only supports P(F) as the stress (and strain) measure.