Add ToolSeparator styling

org.kde.desktop/ToolSeparator.qml

+/*
+    SPDX-FileCopyrightText: 2020 Noah Davis <noahadvs@gmail.com>
+
+    SPDX-License-Identifier: LGPL-3.0-only OR GPL-2.0-or-later
+*/
+
+
+import QtQuick 2.6
+import QtQuick.Templates @QQC2_VERSION@ as T
+import org.kde.kirigami 2.4 as Kirigami
+
+T.ToolSeparator {
+    id: controlRoot
+
+    topPadding: 0
+    bottomPadding: 0
+    leftPadding: Kirigami.Units.smallSpacing
+    rightPadding: Kirigami.Units.smallSpacing
+
+    implicitWidth: separator.width + controlRoot.leftPadding + controlRoot.rightPadding
+    implicitHeight: parent.height
+
+    background: Kirigami.Separator {
+        id: separator
+        anchors {
+            top: controlRoot.top
+            bottom: controlRoot.bottom
+            horizontalCenter: controlRoot.horizontalCenter
+        }
+    }
+}