New simulator block

[VenusPasandi]

With this PR, we

1. add a new simulator block called RobotDynWithContacts_closedChain that is capable of
   • simulating a robot with multiple closed kinematic chains,
   • defining multiple links of the robot as the links interacting with the ground,
2. add a frictional impact model where we consider the friction effects in the impact model (Note that we still use the previous impact model by default. We can the frictional impact by setting the configuration parameter useFrictionalImpact = true),
3. add a discrete contact model where we consider the contact constraints in the velocity level. In the previous contact model, we consider the contact constraints in the acceleration level. (Note that we still use the previous contact model by default. We can use the discrete contact model by setting the configuration parameter useDiscreteContact = true),
4. add a criteria for the maximum acceptable consecutive fails in computing the reaction forces. If the solver fails more than the predefined criteria, the simulator block generates an error. Note that this criteria can be set through the configuration parameter max_consecuitive_fail.

Note that the PR does not change the high-level parameters of the RobotDynWithContacts block which released previously. So, the changes are aligned with the previous use of the repo.

[Giulero]

I haven't tested the changes but I went through the code and looks good to me! :)

[nunoguedelha]

@VenusPasandi just submitted a few comments, just some typos.