Add example for action call

[sampreets3]

Provide an example of sending a goal to an action server, and receiving the result.

NOTE:

• Could be interesting to kill two birds with one stone, by using a different form of accepting input than previously used
• In order to showcase the full potential, make full use of all the capabilities - send_goal, feedback, and result.
• If possible, add a small status bar where we can show that the action goal acceptance status - accepted, aborted, rejected, etc.