Mark all messages as read on current room change

When user enters to the room, all messages from that room should
be already marked as ready without need to e.g. scroll up and then down
to the bottom again.

src/qml/Page/RoomPage.qml

@@ -41,6 +41,7 @@ Kirigami.ScrollablePage {
             } else if (page.currentRoom.isInvite) {
                 page.currentRoom.clearInvitationNotification();
             }
+            currentRoom.markAllMessagesAsRead();
         }
     }
 
@@ -51,6 +52,7 @@ Kirigami.ScrollablePage {
         if (!Kirigami.Settings.isMobile) {
             chatBox.chatBar.forceActiveFocus();
         }
+        currentRoom.markAllMessagesAsRead();
     }
 
     Connections {