Don't use jobs for open group polling

It's not necessary because we can always get the messages again from the server, and it helps with performance

SessionMessagingKit/Sending & Receiving/Pollers/OpenGroupPollerV2.swift

@@ -65,17 +65,22 @@ public final class OpenGroupPollerV2 : NSObject {
         // Sorting the messages by server ID before importing them fixes an issue where messages that quote older messages can't find those older messages
         let openGroupID = "\(server).\(body.room)"
         let messages = body.messages.sorted { $0.serverID! < $1.serverID! } // Safe because messages with a nil serverID are filtered out
-        messages.forEach { message in
-            guard let data = Data(base64Encoded: message.base64EncodedData) else {
-                return SNLog("Ignoring open group message with invalid encoding.")
-            }
-            let envelope = SNProtoEnvelope.builder(type: .sessionMessage, timestamp: message.sentTimestamp)
-            envelope.setContent(data)
-            envelope.setSource(message.sender!) // Safe because messages with a nil sender are filtered out
-            envelope.setServerTimestamp(message.sentTimestamp)
-            let job = MessageReceiveJob(data: try! envelope.buildSerializedData(), openGroupMessageServerID: UInt64(message.serverID!), openGroupID: openGroupID, isBackgroundPoll: isBackgroundPoll)
-            storage.write { transaction in
-                SessionMessagingKit.JobQueue.shared.add(job, using: transaction)
+        storage.write { transaction in
+            messages.forEach { message in
+                guard let data = Data(base64Encoded: message.base64EncodedData) else {
+                    return SNLog("Ignoring open group message with invalid encoding.")
+                }
+                let envelope = SNProtoEnvelope.builder(type: .sessionMessage, timestamp: message.sentTimestamp)
+                envelope.setContent(data)
+                envelope.setSource(message.sender!) // Safe because messages with a nil sender are filtered out
+                envelope.setServerTimestamp(message.sentTimestamp)
+                do {
+                    let data = try envelope.buildSerializedData()
+                    let (message, proto) = try MessageReceiver.parse(data, openGroupMessageServerID: UInt64(message.serverID!), isRetry: false, using: transaction)
+                    try MessageReceiver.handle(message, associatedWithProto: proto, openGroupID: openGroupID, isBackgroundPoll: isBackgroundPoll, using: transaction)
+                } catch {
+                    SNLog("Couldn't receive open group message due to error: \(error).")
+                }
             }
         }
         // - Moderators