Fix excessive cpu consumption

[Zaakhi]

This pull request Fixes issue #91

The issue is caused by the self._state_cb where is going at the same rate of the Controller Manager.

To solve this, the subscriber is created and destroyed every time the action is called using wait_for_message rlcpy function.

Before the fix:

After the fix:

fixes #91

[bmagyar]

Thanks for following up! Which distro would you like this in?

[bmagyar]

@Noel215 if you are also happy please merge

[Zaakhi]

Thanks for following up! Which distro would you like this in?

For now it's humble, thank you very much!