HydroForce engine: update the changes from the last two years
- Modify the averaging function
- Add new mixing length formulation to the fluid resolution
- Add the possibility to apply a lubrication force to HydroForceEngine
- Add the possibility to account for lubrication with an effective restitution coefficient calculated at each interaction in Law2_ScGeom_ViscElCapPhys_Basic
- Add examples (pipe flow, shape variation) and validation scripts (quickvalidation, lubrication)
- Fix minor mistakes and make practical modification + adapt all the examples to the modifications made