[native] add starting payload to send reaction message dispatch action promise
Summary:
add starting payload to send reaction message dispatch action promise. This starting payload is the optimistically created reaction message.
Depends on D6121
Linear Task: ENG-2520
Test Plan: flow and ths will be further tested in a subsequent diff
Reviewers: atul, tomek
Reviewed By: tomek
Subscribers: ashoat, tomek, atul
Differential Revision: https://phab.comm.dev/D6122