Create a DynamicState to store the dynamic solution.

[mvanzulli]

1. Extend this FullStaticState adding:

• [x] Velocity
• [x] Acceleration
• [x] Inertial forces
• [x] Damping Matrix
• [x] Mass Matrix

Check which methods can be defined in an abstract way into the interface.

[mvanzulli]

Done in #484