Move test-06 to GTest API
Move test-06 to GTest API

First pass into replacing the last three numbered tests into named
tests.

Distrotech/json-glib,frida/json-glib,oerdnj/json-glib,brauliobo/json-glib,brauliobo/json-glib,frida/json-glib,Distrotech/json-glib,oerdnj/json-glib,oerdnj/json-glib,robtaylor/json-glib-gvariant,oerdnj/json-glib,GNOME/json-glib,ebassi/json-glib,ebassi/json-glib,GNOME/json-glib,robtaylor/json-glib-gvariant,brauliobo/json-glib,Distrotech/json-glib,ebassi/json-glib