[yarpdataplayer] Provide status flag to check if player has finished playing a loaded dataset

[prashanthr05]

Is your feature request related to a problem? Please describe.

When trying to control the yarpdataplayer through a CPP application using the RPC commands, there is no possibility to check if a single run of an entire loaded dataset has completed, while using the play command.

The application prints the following line to the console while the seek bar reaches the end,
asking utils to stop thread.

Additionally, it would be helpful if yarpdataplayer exposed flags like isStopped, isStoppedAtTheEnd, isRunning, etc.

Describe the solution you'd like

A desirable solution could be adding thrift-based functions to check the status flags through the same RPC interface, while internally updating the required status flags hidden from the user.

Describe alternatives you've considered

An alternative that I've considered so far is to use the RPC command step and advance until a boolean false is returned. However, I have not fully understood the implications this might have on the sampling periods of multi-rate sensors datasets.

[drdanz]

Fixed by #2442