ref-filter: propagate peeled object ID

ref-filter: propagate peeled object ID

When queueing a reference in the "ref-filter" subsystem we end up
creating a new ref array item that contains the reference's info. One
bit of info that we always discard though is the peeled object ID, and
because of that we are forced to use `peel_iterated_oid()`.

Refactor the code to propagate the peeled object ID via the ref array,
if available. This allows us to manually peel tags without having to go
through the object database.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>