[native] Unshim UNSUPPORTED REACTION messages stored in clientDB

Summary: Basically D5638 but for REACTIONs instead of MULTIMEDIA messages.

Test Plan:

1. Uninstall Comm Messenger on my phone
2. Install old build (app store one specifically)
3. Observe the UNSUPPORTED message robotexts
4. Deploy Release build to my phone (with these changes patched in)
5. Observe that reactions show up as expected

Before:

After:

Reviewers: ginsu, ashoat

Reviewed By: ginsu, ashoat

Subscribers: ashoat, tomek

Differential Revision: https://phab.comm.dev/D6023