Contribute new code for DID call type management

Hi Team.

I have modified and added my own code for DID management. I felt the need for ability to add call types of direct IP calling and a simpler version of the "OTHER" call type. I labeled them as Direct-IP and DID@IP/URL. See screenshot. Let me know how and if you would like me to share the code.

The functions are as follows:
Direct-IP uses the number of the DID @ the extension / destination field.
DID@IP/URL is exactly like the "Other" option but it will just prepend sofia/default/<destination> field so you could use it to direct calls to any destination that is SIP URI capable.

Examples:
Direct-IP: DID field = 1235551234 and Destination field = 1.2.3.4
The code behind will dial sofia/default/1235551234@1.2.3.4

DID@IP/URL: DID field = 1235551234 and Destination field = 1234@1.2.3.4
The code behind will dial sofia/default/1234@1.2.3.4