Avoid the need for each driver to parse query parameters itself
by storing them directly in the virURIPtr struct. The parsing
code is a copy of that from src/util/qparams.c  The latter will
be removed in a later patch

* src/util/viruri.h: Add query params to virURIPtr
* src/util/viruri.c: Parse query parameters when creating virURIPtr
* tests/viruritest.c: Expand test to cover params
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>