save server hash for message receive jobs

Session/Utilities/BackgroundPoller.swift

@@ -48,7 +48,7 @@ public final class BackgroundPoller : NSObject {
                         // messages failed to parse.
                         guard let envelope = SNProtoEnvelope.from(json),
                             let data = try? envelope.serializedData() else { return nil }
-                        let job = MessageReceiveJob(data: data, isBackgroundPoll: true)
+                        let job = MessageReceiveJob(data: data, serverHash: json["hash"] as? String, isBackgroundPoll: true)
                         return job.execute()
                     }
                     return when(fulfilled: promises) // The promise returned by MessageReceiveJob never rejects

SessionMessagingKit/Sending & Receiving/Pollers/ClosedGroupPoller.swift

@@ -117,7 +117,7 @@ public final class ClosedGroupPoller : NSObject {
                 guard let envelope = SNProtoEnvelope.from(json) else { return }
                 do {
                     let data = try envelope.serializedData()
-                    let job = MessageReceiveJob(data: data, isBackgroundPoll: false)
+                    let job = MessageReceiveJob(data: data, serverHash: json["hash"] as? String, isBackgroundPoll: false)
                     SNMessagingKitConfiguration.shared.storage.write { transaction in
                         SessionMessagingKit.JobQueue.shared.add(job, using: transaction)
                     }

SessionMessagingKit/Sending & Receiving/Pollers/Poller.swift

@@ -97,7 +97,7 @@ public final class Poller : NSObject {
                 guard let envelope = SNProtoEnvelope.from(json) else { return }
                 do {
                     let data = try envelope.serializedData()
-                    let job = MessageReceiveJob(data: data, isBackgroundPoll: false)
+                    let job = MessageReceiveJob(data: data, serverHash: json["hash"] as? String, isBackgroundPoll: false)
                     SNMessagingKitConfiguration.shared.storage.write { transaction in
                         SessionMessagingKit.JobQueue.shared.add(job, using: transaction)
                     }