Refactored messages Array on client to use a Map

[connor-kress]

For issue #232

This PR refactors the messages state on the client (in <ChatScreen />) from an array (Message[]) to a Map with message IDs as keys (Map<string, Message>). To do this, I also had to add a message ID attribute using a UUID generated with expo-crypto. The messages map is passed to <MessageChannel /> as a map, which is then converted/sorted inside <MessageChannel /> on render.

For future improvements, it may be a good idea to persist a sorted array on the client in addition to the map, so that it does not have to be created and sorted on every rerender. This is not a big problem for now but may introduce some performance costs when scaling to large and quickly updating chats. A hybrid approach may allow for the best of both data structures.

It should also be noted that the current broken state of socket server connection management made it difficult to test this refactor as it could not be run altogether. Instead, I injected some mock data (I left this commented out for others to use) at the broken points as a temporary solution.

[h1divp]

This is a great change. I have started to research how to make it so we won't need to recreate the map on every render, and I think we should look into using a Reducer which will also make implementing reactions nicer. I will make a subsequent issue for this.

This post also seems like a good starting point for figuring out this problem.

Thank you for your work.

[h1divp]

tested, works, lgtm