Possibility to select which supplier contact the call will be directed to.

When we direct a call to a supplier we are restricted to the email address that is 
registered for him, and as there is the possibility of several contacts registered 
for the same supplier, then we could select which contact to send the call to.

So the process would be as follows:

1. Assign the ticket to the supplier;
2. The system shows in the list all the contacts registered for the supplier;
3. We select the desired contact;
4. We confirm the assignment and the system sends the appropriate messages.