delegatesizehelper updates

Make `DelegateSizeHelper` take a `QQuickItem` rather than a width value and move `TimelineDelegate` to use it rather than duplicting the code.

This requires the creation of `LibNeoChat` so that both the main and timeline modules can get access to the class.

Note: ideally more stuff will go into `LibNeoChat` but it turns out our dependencies are kinda spaghetti like and so will take some untangling.

src/qml/SpaceHierarchyDelegate.qml

@@ -10,6 +10,7 @@ import org.kde.kirigamiaddons.delegates as Delegates
 import org.kde.kirigamiaddons.labs.components as Components
 
 import org.kde.neochat
+import org.kde.neochat.libneochat as LibNeoChat
 
 Item {
     id: root
@@ -44,7 +45,7 @@ Item {
 
         anchors.horizontalCenter: root.horizontalCenter
         anchors.verticalCenter: root.verticalCenter
-        width: sizeHelper.currentWidth
+        width: sizeHelper.availableWidth
 
         highlighted: dropArea.containsDrag
 
@@ -201,15 +202,14 @@ Item {
         }
     }
 
-    DelegateSizeHelper {
+    LibNeoChat.DelegateSizeHelper {
         id: sizeHelper
+        parentItem: root
         startBreakpoint: Kirigami.Units.gridUnit * 46
         endBreakpoint: Kirigami.Units.gridUnit * 66
         startPercentWidth: 100
         endPercentWidth: 85
         maxWidth: Kirigami.Units.gridUnit * 60
-
-        parentWidth: root.treeView ? root.treeView.width : 0
     }
 
     Component {

src/qml/SpaceHomePage.qml

@@ -8,6 +8,7 @@ import QtQuick.Layouts
 import org.kde.kirigami as Kirigami
 
 import org.kde.neochat
+import org.kde.neochat.libneochat as LibNeoChat
 import org.kde.neochat.settings
 
 ColumnLayout {
@@ -93,15 +94,14 @@ ColumnLayout {
                 onTextChanged: spaceChildSortFilterModel.filterText = text
             }
         }
-        DelegateSizeHelper {
+        LibNeoChat.DelegateSizeHelper {
             id: sizeHelper
+            parentItem: root
             startBreakpoint: Kirigami.Units.gridUnit * 46
             endBreakpoint: Kirigami.Units.gridUnit * 66
             startPercentWidth: 100
             endPercentWidth: 85
             maxWidth: Kirigami.Units.gridUnit * 60
-
-            parentWidth: root.width
         }
     }
     Kirigami.Separator {