tests: Improve address pool unit tests
tests: Improve address pool unit tests

Add a range with mixed IPV4 and IPV6 addresses to pool.
Get an IPV4 address from an IPV6-only pool.
Get an IPV6 address from an IPV4-only pool.
Reserve a IPV6 address from an IPV4-only pool.
Check for unicast addresses in multicast-only pool.
Check for unicast addresses in uni-/multicast-mixed pool.

https://bugzilla.gnome.org/show_bug.cgi?id=710128

thaytan/gst-rtsp-server,thaytan/gst-rtsp-server,hsteinhaus/gst-rtsp-server,barisdemiray/gst-rtsp-server,hsteinhaus/gst-rtsp-server,hsteinhaus/gst-rtsp-server,surround-io/gst-rtsp-server,barisdemiray/gst-rtsp-server,surround-io/gst-rtsp-server,surround-io/gst-rtsp-server,thaytan/gst-rtsp-server,Lachann/gst-rtsp-server,barisdemiray/gst-rtsp-server,Lachann/gst-rtsp-server,Lachann/gst-rtsp-server