Enable stateful materials in mortar constraints

[recuero]

Reason

Usage of the mortar formulation to the interface problem is expanding. With it, new applications appear that aim to enforce constraints with some dependency on old material properties. This case has taken place, for example, for a thermal problem that depends on one stateful material property.

We could also envision other applications in which stateful materials can be used in a mortar problem. For example, a Nitsche-like approach that requires evaluating stresses.

Design

Additional projections onto the mortar segment mesh will be required to make this work. @lindsayad already has design ideas as to how to carry this out.

Impact

No impact on current capabilities. But a nice one added.

[tophmatthews]

I have a specific use case for thermal conductivity that is dependent on porosity which is stateful. Right now, a simple work around is to degrade the thermal conductivity using an average porosity via a postprocessor. Would be great to see this work!