Update ICub wearable device with virtual link sensors and accelerometers

To realize the idea of doing a validation of `HDE` with icub robot, we need to provide the same kind of data from the `ICub` wearable device, as that of `Xsens Suit` wearable device. As discussed with @diegoferigo and @lrapetti , we need to update the `ICub` device with new sensors. Currently, the `ICub` device has virtual joint sensors implemented https://github.com/robotology-playground/wearables/issues/32 and ft sensors implemented. The keys additions to `ICub` device can be summarized as:

- [x] Implementing virtual link sensors to provide link orientation and velocity. This can be achieved using idyntree model and setting the robot state with the joint quantities already available in the `ICub` device
- [ ] Implementing accelerometer sensors to link acceleration inputs similar to `xsens suit` device. This is not clearly understood at the moment and it has to be investigated a bit more.
- [x] Investigating how to use ft values from the sensors i.e. not wbd wrench estimates. Currently, the ft values are obtained by connecting to a [port passed through the configuration file for the ftsensors](https://github.com/robotology-playground/wearables/blob/1857545b5c500dfac9a57355cb12894c366c516e/app/xml/ICubWearableDevice.xml#L5). We use the `WBD` ports at the moment to get the wrench estimates at the of the robot. Instead, to be similar to the human case, we need to use the ft values from the sensors at the feet of the robot and for this the correct ports are opened [on the robot through wrappers](https://github.com/robotology/robots-configuration/blob/bbc6a318c04ab86029b77d90d74a18bbf8a51061/iCubGenova04/wrappers/FT/right_foot-FT_wrapper.xml#L7).

Once the above updates are added to the `ICub` wearable device, it will stream wearable data that is similar to the `Xsens suit` wearable device. So, in principle, we will be able to test `HDE` with `ICub` wearable device directly to do a validation of the joint torque estimates.

CC @lrapetti @diegoferigo @claudia-lat @DanielePucci @traversaro