Improved itinerary delegates

Steal the look of itinerary items from itinerary but simplified. Also includes new support for flights and restaurants

![image](/uploads/a574d2362edad52ecf91ce89a1849f27/image.png)

src/timeline/TransportIcon.qml

@@ -0,0 +1,46 @@
+/*
+    SPDX-FileCopyrightText: 2023 Volker Krause <vkrause@kde.org>
+    SPDX-License-Identifier: LGPL-2.0-or-later
+*/
+
+import QtQuick
+import QtQuick.Layouts
+import org.kde.kirigami as Kirigami
+
+/** Displays a transport line or mode logo/icon.
+ *  Mainly to hide ugly implementation details of Icon not
+ *  handling non-square SVG assets in the way we need it here.
+ */
+Item {
+    id: root
+    // properties match those of Icon
+    property string source
+    property alias isMask: __icon.isMask
+    property alias color: __icon.color
+
+    // icon size (height for non-square ones)
+    property int size: Kirigami.Units.iconSizes.small
+
+    property bool __isIcon: !source.startsWith("file:")
+
+
+    implicitWidth: __isIcon ? root.size : Math.round(root.size * __image.implicitWidth / __image.implicitHeight)
+    implicitHeight: root.size
+
+    Layout.preferredWidth: root.implicitWidth
+    Layout.preferredHeight: root.implicitHeight
+
+    Kirigami.Icon {
+        id: __icon
+        source: root.__isIcon ? root.source : ""
+        visible: source !== ""
+        anchors.fill: parent
+    }
+    Image {
+        id: __image
+        source: root.__isIcon ? "" : root.source
+        visible: source !== ""
+        anchors.fill: parent
+        fillMode: Image.PreserveAspectFit
+    }
+}