[Constraint][Correction] Enable PrecomputedConstraintCorrection to operate with preconditioned systems

[th-skam]

This is a component that can be very useful for real-time simulations, however it has been neglected.

It pre-computes the compliance matrix by perturbing the dofs with a unit force.

Problems:

• For accurate computations, when using an iterative solver, stricter tolerances must be set during the perturbations. This was only done with CGLinearSolver during the perturbations. It now covers any solver that has tolerance and iterations as Data. Still fragile. A common API for iterative solvers could be useful.
• With preconditioned solvers (such as PCG) the precomputation might break because it relies on finding the linearSolver through getContext. This can return either the preconditioner or the actual solver, depending on how the user set them up in the scene graph. I added a link instead to explicit this and a scene to demonstrate it.