* Progress towards deleting Sockets.Abstractions
- Moved our custom DefaultConnectionContext to Sockets.Http and renamed it to HttpConnectionContext.
- Renamed ConnectionManager to HttpConnectionManager
- Use DefaultConnection in tests and benchmarks
- Delete ConnectionMetadata
- Don't allocate when enumerating connections
- Don't allocate tasks unless we truly go async
- Don't get the timestamp, just write the pings always (if there's no ongoing write)
- Track the time since last keep alive write instead of the last write
- ValueTask all the things!
- Renamed HubConnectionList to HubConnectionStore
* Remove the Channel<HubMessage> from the HubConnectionContext
- Replace the channel with a single lock around the pipewriter. Since writes are always synchronous, the lock is held for a very short time.
- We were only using them in this scenario for handling multiple producers (the hub output, the keep alive ping and the broadcast).
- Handle the scenario where there's back pressure (when we use pipes that are bounded) and give callers a single task representing when back pressure is released.
- Handle synchronous exceptions in RedisHubLifetimeManager
- Fixed benchmarks