iCubGazebo2_5_visuomanip: provide port names consistent with the real robot

[traversaro]

See #44 (comment) .

In particular, according to #44 (comment) the real robot publishes RGB images as:

• /icub/cam/right
• /icub/cam/left

While the Gazebo simulated robot:

• /icubSim/cam/left/rgbImage:o
• /icubSim/cam/right

[xEnVrE]

I am considering again this issue, after #195 and vvv-school/assignment_make-it-roll#9.

At the moment, we can only decide the initial part of the port name:

icub-models/iCub_manual/conf_manual/iCubGazeboV2_5_visuomanip/wrappers/camera/left_camera-rgbd_wrapper.xml

Lines 4 to 6 in 5627eea

	<device xmlns:xi="http://www.w3.org/2001/XInclude" name="left_camera_rgbd_nws_yarp" type="rgbdSensor_nws_yarp">
	<param name="period">0.033</param>
	<param name="name"> ${portprefix}/cam/left </param>

To solve the problem from the root, what is missing is having the possibility to decide the final part of the port names within the rgbdSensor_nws_yarp device.

The final part of the ports is hardcoded at the moment, as can be seen in https://github.com/robotology/yarp/blob/03a47d532b048bd862eb763c58badf2f7576847d/src/devices/RGBDSensor_nws_yarp/RgbdSensor_nws_yarp.cpp#L255.

Changing that behavior would imply adding some parameters and proper defaults to avoid the necessity to change a huge number of configuration files.

cc @pattacini