Cleanup leftover issues from moving ReplyComponent away from GridLayout

Cleanup leftover issues from moving ReplyComponent away from GridLayout.
- Remove leftover GridLayout properties or references to them or convert as required
- Remove unneeded Item wrapper

src/qml/ReplyComponent.qml

@@ -20,7 +20,7 @@ import org.kde.neochat
  * show in their original form and are instead visualised with a MIME type delegate
  * e.g. Videos.
  */
-Item {
+RowLayout {
     id: root
 
     /**
@@ -75,19 +75,11 @@ Item {
      */
     signal replyClicked()
 
-    implicitWidth: mainLayout.implicitWidth
-    implicitHeight: mainLayout.implicitHeight
-
-    RowLayout {
-        id: mainLayout
-        anchors.fill: parent
     spacing: Kirigami.Units.largeSpacing
 
     Rectangle {
         id: verticalBorder
-
         Layout.fillHeight: true
-            Layout.rowSpan: 2
 
         implicitWidth: Kirigami.Units.smallSpacing
         color: root.author.color
@@ -151,7 +143,6 @@ Item {
         acceptedButtons: Qt.LeftButton
         onTapped: root.replyClicked()
     }
-    }
 
     Component {
         id: textComponent
@@ -176,13 +167,13 @@ Item {
             width: mediaSizeHelper.currentSize.width
             height: mediaSizeHelper.currentSize.height
             fillMode: Image.PreserveAspectFit
-            source: root.mediaInfo.source
+            source: root?.mediaInfo.source ?? ""
 
             MediaSizeHelper {
                 id: mediaSizeHelper
-                contentMaxWidth: root.contentMaxWidth - verticalBorder.width - mainLayout.columnSpacing
-                mediaWidth: root.mediaInfo.width
-                mediaHeight: root.mediaInfo.height
+                contentMaxWidth: root.contentMaxWidth - verticalBorder.width - root.spacing
+                mediaWidth: root?.mediaInfo.width ?? -1
+                mediaHeight: root?.mediaInfo.height ?? -1
             }
         }
     }