Improve loading speed on home timeline

This commit improves the loading speed for the home timeline (and likely
other areas of the app) by employing various techniques and changes:
- Network EOSE timeout reduced from 10 seconds down to 5 seconds
- Network EOSE does not wait on relays with broken connections
- Offload HomeModel handler event processing to separate tasks to
  avoid a large backlog
- Give SubscriptionManager streamers more fine-grained EOSE signals for
  local optimization
- Only wait for Ndb EOSE on the home timeline for faster loading
- Add logging with time elapsed measurements for easier identification of
  loading problems

Signed-off-by: Daniel D’Aquino <daniel@daquino.me>

damus/Core/Nostr/RelayPool.swift

@@ -232,11 +232,13 @@ class RelayPool {
     ///   - desiredRelays: The desired relays which to subsctibe to. If `nil`, it defaults to the `RelayPool`'s default list
     ///   - eoseTimeout: The maximum timeout which to give up waiting for the eoseSignal
     /// - Returns: Returns an async stream that callers can easily consume via a for-loop
-    func subscribe(filters: [NostrFilter], to desiredRelays: [RelayURL]? = nil, eoseTimeout: Duration? = nil) -> AsyncStream<StreamItem> {
-        let eoseTimeout = eoseTimeout ?? .seconds(10)
-        let desiredRelays = desiredRelays ?? self.relays.map({ $0.descriptor.url })
+    func subscribe(filters: [NostrFilter], to desiredRelays: [RelayURL]? = nil, eoseTimeout: Duration? = nil, id: UUID? = nil) -> AsyncStream<StreamItem> {
+        let eoseTimeout = eoseTimeout ?? .seconds(5)
+        let desiredRelays = desiredRelays ?? self.relays.filter({ $0.connection.isConnected }).map({ $0.descriptor.url })
+        let startTime = CFAbsoluteTimeGetCurrent()
         return AsyncStream<StreamItem> { continuation in
-            let sub_id = UUID().uuidString
+            let id = id ?? UUID()
+            let sub_id = id.uuidString
             var seenEvents: Set<NoteId> = []
             var relaysWhoFinishedInitialResults: Set<RelayURL> = []
             var eoseSent = false
@@ -257,6 +259,7 @@ class RelayPool {
                         break   // We do not support handling these yet
                     case .eose(_):
                         relaysWhoFinishedInitialResults.insert(relayUrl)
+                        Log.debug("RelayPool subscription %s: EOSE from %s. EOSE count: %d/%d. Elapsed: %.2f seconds.", for: .networking, id.uuidString, relayUrl.absoluteString, relaysWhoFinishedInitialResults.count, Set(desiredRelays).count, CFAbsoluteTimeGetCurrent() - startTime)
                         if relaysWhoFinishedInitialResults == Set(desiredRelays) {
                             continuation.yield(with: .success(.eose))
                             eoseSent = true