sending OSC-value feedback working

if a widget is listening to some external OSC-controller it can now send
the CV's input (0.0-1.0) back to that controller - deactivated by
default but can be activated within the widget's actions with one click.
The necessary action will automatically be added to the widget's action
when creating the OSC-connection and removed upon disconnection

Signed-off-by:  <st9fan@gmail.com>
don't automatically activate OSC-feedback when creating an OSC-connection

Signed-off-by:  <st9fan@gmail.com>