Cannot clone sequences with attached events in different sequences

[Mgamerz]

Describe the bug
There is an error when cloning a sequence that references events in other sequences via AttachToEvent. This is a problem in vanilla game files.

To Reproduce
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LE2 BioD_EndGm2_120TheHives.pcc (basegame):

1. Go to sequence 6245 Seq_FlyIn_LowerSection
2. Go to 6261 SequenceReference (Spawn Flyer / Spawn Complete)
3. Attempt to clone the object. It will fail as it cannot find some of the items its trying to clone

Expected behavior
It works.

Screenshots and files used to replicate this
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Version information:
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Nightly

Info
Debugging this indicates its looking for objects in the CURRENT sequence to clone. However, AttachToEvent seems to be able to reference
objects in other sequences that are not in the local one. In this case, 5936 and 5937 SeqAction_AttachToEvent is attaching to objects in subsequences. I'm not sure how to resolve this; unless you collected all objects in subsequences as well and did another pass to link them up after clone. No matter what is done it's going to be a PITA to fix.