[multidomain,localoperator] Outsource boundaryLayerModel and massTransferModel.

This has the following advantages:
 - reuse the BL model in the non-isothermal case
 - possible move of the functions to more problem specific place (due to the use of runtime parameters)
 - better comparison of what is actually done in the code

Update reference solution, because for the BL Model the gas viscosity from Darcy was used.