The wellModel is now persistent over the time steps,
with an update method called every reportStep/episode.
This allows the following simplifications:
1. move the wellState to the WellModel
2. add a ref to the ebosSimulator to the wellModel
3. clean up the parameters passed to the wellModel methods
4. move RESV handling to the WellModel and the rateConverter
5. move the econLimit update to the WellModel
The surface density input in well_perforation_densities() in
WellDensitySegmented.hpp is changed from one value pr. phase to one
value pr phase and perforation. This allow for different densities in
different perforation. The test is changed accordingly.
Conflicts:
opm/autodiff/FullyImplicitBlackoilSolver.cpp
To resolve conflicts, WellState was changed to WellStateFullyImplicitBlackoil
in multiple places, and perfRate() changed to perfPhaseRate() in
WellDensitySegmented.