Introduce canInvitePeople on bubble cell data

Riot/Modules/MatrixKit/Models/Room/MXKRoomBubbleCellData.m

@@ -701,6 +701,13 @@
     return res;
 }
 
+- (BOOL)canInvitePeople
+{
+    NSInteger requiredLevel = roomDataSource.roomState.powerLevels.invite;
+    NSInteger myLevel = [roomDataSource.roomState.powerLevels powerLevelOfUserWithUserID:roomDataSource.mxSession.myUserId];
+    return myLevel >= requiredLevel;
+}
+
 - (NSArray*)events
 {
     NSMutableArray* eventsArray;