Client v2

[oscartbeaumont]

Extracted from #326

Typescript Client:

• BigInt support on client through json-with-bigint
• WithDate decoder (gotta figure out how to merge with json-with-bigint)
• Ensure files uploads are sorted last in the request (as they are blocking).
• How will we integrate React Query with the response output (as rspc_invalidation can return queries that were not requested)
• Extra metadata to implement a split link
• Return cleanup closure from fetch fn so we can abort subscriptions
• Batch stream link that does streaming request body instead of a timeout on the client. Will reduce latency.