iOS: accept images in NSE if enabled, reorder chats when coming from background (#800)

* ios: automatically accept images in NSE, if enabled in settings

* remove unnecessary TODOs

* reorder chat when coming from background

apps/ios/SimpleXChat/AppGroup.swift

@@ -13,6 +13,7 @@ let GROUP_DEFAULT_APP_STATE = "appState"
 let GROUP_DEFAULT_DB_CONTAINER = "dbContainer"
 public let GROUP_DEFAULT_CHAT_LAST_START = "chatLastStart"
 let GROUP_DEFAULT_NTF_PREVIEW_MODE = "ntfPreviewMode"
+let GROUP_DEFAULT_PRIVACY_ACCEPT_IMAGES = "privacyAcceptImages"
 
 let APP_GROUP_NAME = "group.chat.simplex.app"
 
@@ -59,6 +60,8 @@ public let ntfPreviewModeGroupDefault = EnumDefault<NotificationPreviewMode>(
     withDefault: .message
 )
 
+public let privacyAcceptImagesGroupDefault = BoolDefault(defaults: groupDefaults, forKey: GROUP_DEFAULT_PRIVACY_ACCEPT_IMAGES)
+
 public class DateDefault {
     var defaults: UserDefaults
     var key: String
@@ -103,3 +106,22 @@ public class EnumDefault<T: RawRepresentable> where T.RawValue == String {
         defaults.synchronize()
     }
 }
+
+public class BoolDefault {
+    var defaults: UserDefaults
+    var key: String
+
+    public init(defaults: UserDefaults = UserDefaults.standard, forKey: String) {
+        self.defaults = defaults
+        self.key = forKey
+    }
+
+    public func get() -> Bool {
+        defaults.bool(forKey: key)
+    }
+
+    public func set(_ value: Bool) {
+        defaults.set(value, forKey: key)
+        defaults.synchronize()
+    }
+}