While currently, all cases where `BKE_id_owner_get` is called are
'safe', there are some points in code where the pointers ensureing the
relationship between an embedded ID and its owner are not (fully) valid.
This new option (`false` by default) allows to skip the debug asserts
ensuring the sanity of these 'owner <-> embedded' ID pointers in the
relevant `owner_pointer_get` callbacks.
This change is not expected to have any effect in current codebase.
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