EZC: fix ref counts in _object_and_properties_init()

In _object_and_properties_init() a.k.a. object_init_ex(), the ObjectData was created and returned to userspace with a refcount of zero, despite being referred to by the RefData. Also, the RefData was inappropriately incref'd, making it unconditionally leak.

The two bugs cancelled out in a common case -- calling tvUnbox() on the RefData caused the ObjectData to be incref'd, leaving it with the correct refcount if you discount the leaked, unreachable RefData. Added a test case showing a less common case which previously failed.

Should fix https://bugzilla.wikimedia.org/show_bug.cgi?id=65796