[native] introduce functionality to send a reaction by pressing on the reaction pill.

Summary:
To improve the user experience of the InlineEngagement component we are updating the pressing behavior for our reaction pills. Before whenever a user would press on a reaction, the MessageReactionsModal would slide in, but now if a user presses a reaction they will react/unreact to that message depending on whether or not they have already reacted to that message already. To view the MessageReactionsModal the user now needs to long press on the reaction pill (a similar pattern with other chat apps such as discord and slack)

Depends on D8576

Test Plan:
Please watch the demo below

Reviewers: atul, kamil

Reviewed By: kamil

Subscribers: ashoat, tomek

Differential Revision: https://phab.comm.dev/D8578