tests: merge code for UNIX and TCP socket testing
tests: merge code for UNIX and TCP socket testing

The test code for UNIX and TCP sockets will need to be rewritten and
extended later, and will benefit from code sharing.

Reviewed-by: Andrea Bolognani <3ada0bee826c753786fdbba72243dfba997094cf@redhat.com>
Signed-off-by: Daniel P. Berrangé <bb938cf255e055ff3507f2627d214e8e62118fcf@redhat.com>

crobinso/libvirt,fabianfreyer/libvirt,nertpinx/libvirt,jfehlig/libvirt,andreabolognani/libvirt,nertpinx/libvirt,olafhering/libvirt,fabianfreyer/libvirt,libvirt/libvirt,eskultety/libvirt,jfehlig/libvirt,jfehlig/libvirt,eskultety/libvirt,crobinso/libvirt,nertpinx/libvirt,nertpinx/libvirt,jardasgit/libvirt,zippy2/libvirt,olafhering/libvirt,zippy2/libvirt,zippy2/libvirt,jardasgit/libvirt,libvirt/libvirt,fabianfreyer/libvirt,fabianfreyer/libvirt,olafhering/libvirt,libvirt/libvirt,fabianfreyer/libvirt,jardasgit/libvirt,nertpinx/libvirt,libvirt/libvirt,jfehlig/libvirt,olafhering/libvirt,andreabolognani/libvirt,crobinso/libvirt,jardasgit/libvirt,andreabolognani/libvirt,crobinso/libvirt,andreabolognani/libvirt,eskultety/libvirt,eskultety/libvirt,jardasgit/libvirt,zippy2/libvirt,andreabolognani/libvirt,eskultety/libvirt