Swift 6 and Concurrency update

[Cordavi]

What it Does

• Updates Provider to have strict concurrency turned on as well as Swift 6
• Goes through and conforms various types to Sendable
• Uses nonisolated(unsafe) and then manually manages the thread safety when needed for mutability.

How I Tested

• Built the app, ran the test repeatedly 100 times to make sure they pass

Notes

• There is an issue where if you call one of the combine based network calls from the main thread and then do things on any other thread as part of the returned combine chain, the app will crash without a compiler warning. Used @MainActor to enforce it being called from the thread and then always receiving on that thread. I can't scope it to something like the MainQueueScheduler we have in ViewStore, so I updated the docs to call it out.
• Most of the places we are using nonisolated(unsafe) we likely should move from classes to actors so that their mutable state is thread safe without managing it ourselves.
• That felt like a bigger change so will be a follow refactor