Add Reactions for Geochemistry and a ReactiveMultiFluidModel

[CusiniM]

In this PR we

• [x] Create ReactiveMultiFluid model that:
  • [x] adds Equilibrium and KineticReactions and all reactions related quantities
  • [x] serves as base class to all reactive models
  • [x] owns EquilibriumReactions and KineticReactions and interfaces with them.
• [x] Create ReactiveBrineFluid model that:
  • [x] adds a single phase (brine) with its own constitutive laws for viscosity, density, etc.
  • [x] handles conversion from standard compositional variables to what's needed for geochem (volumetric concentrations)
• [x] Add WaterDensity model to have a simple density model for the brine that does not depend on the phase composition.
• [x] Add two type of reactions:
  • [x] Equilibrium reactions
  • [x] kinetic reactions
• [x] Create a dedicated ReactiveFluidDriver to test Reactions.
• [ ] Test implementation for a few specific examples:
  • [x] equilibrium reactions
  • [ ] kinetic reactions
• [x] Split linearAlgebra and denseLinearAlgebra into 2 separate components (needed to avoid having constitutive depending on linearAlgebra which would also create a circular dependency).

The ReactiveFluidDriver can be run from the build directory with

./tests/testReactiveFluid -i ../src/coreComponents/unitTests/constitutiveTests/testReactiveFluid.xml

[CusiniM]

@francoishamon, @klevzoff I think this is ready for a first round of comments while I am gone. Ignore the std::output which is there for @jiyer28 to validate the implementation against her matlab code.