acl-plugin: split the "show" commands and add an option to show ACLs by interface
acl-plugin: split the "show" commands and add an option to show ACLs by interface

From the troubleshooting perspective, it is nice to immediately know
the ACEs for the ACLs applied to an interface, so implement that.

To make the CLI more friendly, split each of the "show" variants
into an independent _cmd function with the distinct CLI path.

Change-Id: I519e4799083c04e8f0fcdf3e262a73493be4b690
Signed-off-by: Andrew Yourtchenko <eb6233fe2fbd585844f4fb8426b53b186ab379b1@gmail.com>

chrisy/vpp,FDio/vpp,vpp-dev/vpp,vpp-dev/vpp,FDio/vpp,FDio/vpp,FDio/vpp,chrisy/vpp,FDio/vpp,chrisy/vpp,FDio/vpp,vpp-dev/vpp,chrisy/vpp,chrisy/vpp,vpp-dev/vpp,vpp-dev/vpp,chrisy/vpp,FDio/vpp,vpp-dev/vpp,vpp-dev/vpp,chrisy/vpp,FDio/vpp,chrisy/vpp