menu: enhancements

- changes that make easier to use menu as module UI
- new helper method for delayed callbacks
- method for getting the menu instance from display
- new action for sending menu:action events
- allow_without_selection option for cards

Signed-off-by: Janar Sööt <janar.soot@gmail.com>

config/example-menu.cfg

@@ -85,6 +85,7 @@
 #   and [respond response_info] command. Respond command will send '// response_info' to host.
 
 #[menu input1]
+#type: input
 #name:
 #cursor:
 #width:
@@ -197,3 +198,8 @@
 #   This way only simple menu items can be grouped.
 #   Example: 5,prt_time, prt_progress - elements prt_time and prt_progress are switched after 5s
 #   Example: msg,xpos|ypos - elements xpos and ypos are grouped and showed together when msg is disabled.
+#use_cursor:
+#   This attribute accepts static boolean value.
+#   When enabled the menu system uses a cursor instead of blinking to visualize item selection
+#   and edit mode for this card. Cursor and placeholder is always added as item name prefix.
+#   The default is False. This parameter is optional.