add slide-in applet dock with collapsible cards, edge trigger, and bar module toggle

shell/modules/DockModule.qml

@@ -0,0 +1,15 @@
+import QtQuick
+import "." as M
+import "../services" as S
+import "../dock" as D
+
+M.BarModule {
+    id: root
+    tooltip: D.DockState.open ? "Close dock" : "Open dock"
+    onTapped: D.DockState.toggle()
+
+    M.BarIcon {
+        icon: D.DockState.open ? "\uDB80\uDD8B" : "\uDB80\uDD89"
+        anchors.verticalCenter: parent.verticalCenter
+    }
+}