Mock microphone and camera

User Story/Description

As a Developer I want to be able to mock camera and microphone data so that things dependent on these still can be developed if Pepper crashes and cannot be used for while

Definition of Done

Microphone and Camera can be started with a launch file specifying parameter so they are mocked by using external webcam and microhpone.

How

Probably adding ROS parameters to microphone_component and camera_component to be able to receive parameters on startup deciding to mock or not. Will probably need to link some dev volumes to give access to microphone and camera in the container.

Microphone: The library PulseAudio might work well.

Camera: Poll the webcam?