Implement isTyping property of MLContact

Monal/Classes/MLContact.h

@@ -72,6 +72,7 @@ FOUNDATION_EXPORT NSString* const kAskSubscribe;
  */
 @property (nonatomic, copy) NSString* statusMessage;
 @property (nonatomic, readonly) NSDate* _Nullable lastInteractionTime;
+@property (nonatomic, readonly) BOOL isTyping;
 
 /**
  used to display the badge on a row

Monal/Classes/MLContact.m

@@ -51,6 +51,7 @@ @interface MLContact ()
 @property (nonatomic, strong) NSSet<NSString*>* rosterGroups;
 
 @property (nonatomic, strong) NSDate* _Nullable lastInteractionTime;
+@property (nonatomic, assign) BOOL isTyping;
 
 @property (nonatomic, assign) NSInteger unreadCount;
 
@@ -286,9 +287,11 @@ -(void) handleLastInteractionTimeUpdate:(NSNotification*) notification
 
     if(![self.contactJid isEqualToString:data[@"jid"]] || self.accountID.intValue != notificationAccountID.intValue)
         return;     // ignore other accounts or contacts
-    if(data[@"lastInteraction"] == nil)
-        return;     // ignore typing notifications
 
+    self.isTyping = [data[@"isTyping"] boolValue];
+
+    if(data[@"lastInteraction"] == nil)
+        return;
     //this will be nil if "urn:xmpp:idle:1" is not supported by any of the contact's devices
     DDLogVerbose(@"Updating lastInteractionTime=%@ of %@", data[@"lastInteraction"], self);
     self.lastInteractionTime = nilExtractor(data[@"lastInteraction"]);