Modify tactile_receiver to deal with Optoforce

[toliver]

Currently it only deals with sensors integrated in-hand (published on e.g. /rh_tactile topic)

https://github.com/shadow-robot/sr_core/blob/indigo-devel/sr_hand/scripts/sr_hand/tactile_receiver.py

Check example created by @beatrizleon

/optoforce_0
/optoforce_1
...

Attention should be payed to the issue of associating these topic names with a particular hand in a multi-hand environment.

[beatrizleon]

https://github.com/shadow-robot/sr_interface/blob/indigo-devel/sr_example/scripts/sr_example/hand_examples/sr_hand_optoforce_tactile_example.py