Remove virutil.h where possible

Remove virutil.h where possible

Historically, this file was a dump for most of our helper
functions and needed almost everywhere.
With the introduction of virfile.h and virstring.h,
and more importantly, virenum.h and the introduction
of GLib, that is no longer true.

Remove its include from C files that don't even use it.

Signed-off-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>