[Joint Trajectory Controller] Add parameters for special cases

[destogl]

Implements the following special cases:

1. JTC can be used for open-loop control. States from the hardware are read when starting the controller. This enables its use for robots/manipulators which have offset between command and states, e.g., often the case with hydraulics manipulators.
2. JTC can deduce position and velocity when positions or accelerations are as input in JointTrajectory.

The PR depends on #140

[bmagyar]

Please split this into 2 PRs

• open-loop mode
• deduce position and velocity

[destogl]

Please split this into 2 PRs

* open-loop mode

* deduce position and velocity

Done in #189 and #190.