[native] Introduce getRelatedMessages to CommCoreModule

Summary:
This diff introduces the code on native to interface with our new getRelatedMessages API.

Depends on D12738

Test Plan:

1. In combination with later diffs, I tested a patch on both native and web that hit getRelatedMessages with a specific message ID and confirmed that it returned the message
2. I tested a message ID that did not exist and confirmed I got undefined back

Reviewers: kamil, tomek, marcin

Reviewed By: marcin

Differential Revision: https://phab.comm.dev/D12739