util: Move enum convertors into virenum.(c|h)

virutil.(c|h) is a very gross collection of random code. Remove the enum
handlers from there so we can limit the scope where virtutil.h is used.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>

tools/virt-host-validate-common.h

@@ -25,6 +25,7 @@
 # include "internal.h"
 # include "virutil.h"
 # include "virbitmap.h"
+# include "virenum.h"
 
 typedef enum {
     VIR_HOST_VALIDATE_FAIL,