MultiDomain does not work for solution-dependent spatial params in instationary problems
This issue is related to #619, #703 and #788 (closed).
What happened / Problem description:
If a spatial param, e.g. porosity, depends on the solution of another domain (for example deformation-dependent porosities in poroelastic models), there is currently no way to evaluate it on the correct time level during the creation of the previous volume variables. This causes the Newton solver to fail even for simple problems. A local (hacky) bugfix showed that good convergence is obtained when this is fixed. This means that currently the Geomechanics module cannot be used for time-dependent problems in which deformation-dependent porosities are used, which is a standard capability.
A similar problem is reported in #703, where time-dependent spatial saturation distributions are needed.
Since several issues are related to this, an idea was to think about a more general way of handling time discretization schemes and hopefully fix all three issues at once.
One idea was to have a local view on the spatial parameters as well, and change all bind functions such that they not only bind to an element but also to a time level somehow.