As the VyOS CLI grows we need to maintain it.

One way to do so was the introduction in VyOS 1.3 to use #include statements well known from C. An #include block shares a common CLI node e.g. "source-address" with a simple implementation.
That building block is later reused across different sections inside the CLI.

From time to time new features are added the need the same - or almost the same CLI syntax. This task is more of a maintenance one to add missing include definitions and refactor the code consuming them,
to make every maintainers life a little less stressful.