Let escape presses work properly inside HDrawer

Also add escape to clear member filter when focusing the field, and
clearMemberFilterOnEscape setting.

src/gui/Base/HDrawer.qml

@@ -24,7 +24,7 @@ Drawer {
     position: 1
     visible: ! collapse
     modal: false
-    closePolicy: Popup.CloseOnEscape
+    closePolicy: Popup.NoAutoClose
 
     background: Rectangle { id: bg; color: theme.colors.strongBackground }