Change vverify() to return HV or NULL (RT#78286)

Change vverify() to return HV or NULL (RT#78286)

Multiple code paths were dereferencing version objects without
checking the underlying type, which could result in segmentation
faults per RT#78286

This patch consolidates all dereferencing into vverify() and
has vverify return the underlying HV or NULL instead of
a boolean value.