Support replying and editing messages directly from room search

There's two parts to making this work mainly:
1. Use getEvent instead of findInTimeline so the related event is
actually found.
2. Close the dialog once a reply relation is found, so you can easily
reply in the chat bar.

src/timeline/MessageDelegate.qml

@@ -227,6 +227,7 @@ MessageDelegateBase {
     quickActionComponent: QuickActions {
         room: root.room
         eventId: root.eventId
+        author: root.author
     }
 
     QtObject {

src/timeline/QuickActions.qml

@@ -22,6 +22,15 @@ RowLayout {
      */
     required property string eventId
 
+    /**
+     * @brief The message author.
+     *
+     * A Quotient::RoomMember object.
+     *
+     * @sa Quotient::RoomMember
+     */
+    required property var author
+
     property real availableWidth: 0.0
 
     property bool reacting: false