[ifsolver] Check if reconstruction is necessary

What this MR does / why does DuMux need it:

It checks if the reconstruction necessary. For an scv with minimal entry pressure, we don't need to apply inverse pc function, etc. For the changes in !3955 this actually leads to a better Newton convergence. This is probably since p_c^{-1}(p_c(s_w)) includes numerical errors which can be omitted with this fix. Edit: This is likely because it avoids in this case the cutoff function which only makes sense for control volumes with differing parameters. Avoiding the cutoff makes sure that in the case of equal parameters, we avoid introducing jumps or kinks in the functional.

This is also probably why we need now 18 time steps less, i.e. 46 instead of 64, which is a high efficiency increase.

Additionally, runtime should be faster since we omit evaluation of costly functions. Simple equality check of parameters should be faster.