Add DSCP configuration support for each individual ASP
Introduce VTY command to configure the Differentiated Services Code
Point (DSCP) values for each Application Server Process.
If the ASP connection has the role "server", it will inherit the DSCP
settings of the listener, unless it is configured at the ASP connection.
Related: SYS#8071
Change-Id: Ia125a392eec5605553809774162675b5249b8494
