Cleanup/remove outdated deprecations

What this MR does / why does DuMux need it:

This merge request removes the support of a few deprecated interfaces. Moreover, with the changes introduced in !1684 (merged), a few things in the transmissibility computations for mpfa could be simplified. In particular, this MR removes the tensorlambdafactory :).

This is WIP because it depends on !1684 (merged) and has to be tested still. Moreover, I guess the old effective thermal conductivity interfaces in ThermalConductivitySomerton etc can also be removed.(edit: already implemented in !1879 (merged)).