[#1288] Extend SyncStatus with stopped state

- InternalSyncStatus as well as SyncStatus were extended with stopped state, this is needed to distinguish between upToDate and stopped via stop() method states as previously stopped state of block processor was mapped to upToDate

Example/ZcashLightClientSample/ZcashLightClientSample/Send/SendViewController.swift

@@ -316,6 +316,9 @@ extension SDKSynchronizer {
         case .unprepared:
             return "Unprepared 😅"
 
+        case .stopped:
+            return "Stopped"
+
         case .error(ZcashError.synchronizerDisconnected):
             return "disconnected 💔"
 

Example/ZcashLightClientSample/ZcashLightClientSample/Sync Blocks/SyncBlocksListViewController.swift

@@ -64,7 +64,7 @@ class SyncBlocksListViewController: UIViewController {
             loggerProxy.debug("Processing synchronizer with alias \(synchronizer.alias.description) \(index)")
 
             switch syncStatus {
-            case .unprepared, .upToDate, .error(ZcashError.synchronizerDisconnected), .error:
+            case .unprepared, .upToDate, .error(ZcashError.synchronizerDisconnected), .error, .stopped:
                 do {
                     if syncStatus == .unprepared {
                         _ = try! await synchronizer.prepare(
@@ -145,7 +145,7 @@ extension SyncBlocksListViewController: UITableViewDataSource {
 
         let image: UIImage?
         switch synchronizerStatus {
-        case .unprepared, .upToDate, .error(ZcashError.synchronizerDisconnected), .error:
+        case .unprepared, .upToDate, .error(ZcashError.synchronizerDisconnected), .error, .stopped:
             image = UIImage(systemName: "play.circle")
         case .syncing:
             image = UIImage(systemName: "stop.circle")
@@ -176,6 +176,8 @@ extension SyncStatus {
             return "Up to Date 😎"
         case .unprepared:
             return "Unprepared"
+        case .stopped:
+            return "Stopped"
         case .error(ZcashError.synchronizerDisconnected):
             return "Disconnected"
         case let .error(error):

Example/ZcashLightClientSample/ZcashLightClientSample/Sync Blocks/SyncBlocksViewController.swift

@@ -93,7 +93,7 @@ class SyncBlocksViewController: UIViewController {
                 metricLabel.text = currentMetricName + report.debugDescription
             }
 
-        case .upToDate:
+        case .upToDate, .stopped:
             accumulateMetrics()
             summaryLabel.text = "enhancement: \(accumulatedMetrics.debugDescription)"
             overallSummary()
@@ -205,7 +205,7 @@ class SyncBlocksViewController: UIViewController {
         switch state {
         case .syncing:
             return "Pause"
-        case .unprepared:
+        case .unprepared, .stopped:
             return "Start"
         case .upToDate:
             return "Chill!"
@@ -222,6 +222,8 @@ class SyncBlocksViewController: UIViewController {
             return "Up to Date 😎"
         case .unprepared:
             return "Unprepared"
+        case .stopped:
+            return "Stopped"
         case .error(ZcashError.synchronizerDisconnected):
             return "Disconnected"
         case .error:

Sources/ZcashLightClientKit/Synchronizer.swift

@@ -317,6 +317,9 @@ public enum SyncStatus: Equatable {
     /// When set, a UI element may want to turn green.
     case upToDate
 
+    /// Indicates that this Synchronizer was succesfully stopped via `stop()` method.
+    case stopped
+    
     case error(_ error: Error)
     
     public var isSyncing: Bool {
@@ -347,6 +350,7 @@ public enum SyncStatus: Equatable {
         switch self {
         case .unprepared: return "unprepared"
         case .syncing: return "syncing"
+        case .stopped: return "stopped"
         case .upToDate: return "up to date"
         case .error: return "error"
         }
@@ -469,7 +473,7 @@ extension InternalSyncStatus {
         case .synced:
             return .upToDate
         case .stopped:
-            return .upToDate
+            return .stopped
         case .disconnected:
             return .error(ZcashError.synchronizerDisconnected)
         case .error(let error):