Ability to add a "stop time" for each marker/stop point

[MrRedness]

This way, you could change how long the robot waits at a marker/stop point without having to change it in code and redeploy. I would be happy to work on this when I have a little bit more time.

[mjansen4857]

This was suggested before and I sort of decided against it since I couldn't think of a way to implement it that I'd be happy with. The best way I thought of was just adding another stationary state to the end of the trajectory for X seconds but that seems a bit hacky. Also this would make it impossible to run the same path without the wait time if you wanted.

After thinking about it a bit another possibility I could think of that would probably be ok is having each trajectory have its own getEndWaitTime method or something like that to return the wait time that was chosen for the stop point in the GUI. Then just do something like this:

new SequentialCommandGroup(
    new PPSwerveControllerCommand(pathGroup[0], ...),
    new WaitCommand(pathGroup[0].getEndWaitTime()),
    new PPSwerveControllerCommand(pathGroup[1], ...),
    new WaitCommand(pathGroup[1].getEndWaitTime())
)

and then you could choose whether you use that wait command or not.

If you think that's good enough I'm happy with that solution. I can work on it whenever so I could take this up if you'd like.

[MrRedness]

That seems like a great solution! Our team does not use command groups, but we could easily adapt our code to using something like getEndWaitTime(). I especially like the new "path groups" feature, as it would also allows different behavior on each segment of the path, something which we had to work around in the past.

[mjansen4857]

Ok, transferred this to #130