support also action servers and clients

[padhupradheep]

enables behavior trees from Nav2 to be access by Pilot

[padhupradheep]

At the moment, we are dropping the plans to bridge Nav2 and Pilot. The focus now would be bridge the communication between the frameworks. Later when the situation arises, then we'll take a look at it once again.

But the issue is still valid, since other hardware like Elite arms requires ROS actions for the goals to be set from the application code. A demo of that would be idle to showcase that Pilot can be also used for mobile manipulators.