Menu creation mechanism

[mlopezFC]

These are the guidelines that we should follow in order to implement a mechanism for building a menu for an application:

• The menu should be assembled in the client side, but obtaining the menu options from the server side
• It should be a mechanism for adding menu items from the client side (for pure client side functionalities) in a project that is using commons-vaadin
• The mechanism for obtaining the menus from the server side should be provided by commons-vaadin
• If for some reason the server side items cannot be obtained the menu should be displayed anyway
• Components like dynamic-menu should be able to contribute to building the menu obtaining the items from other places (ie: db)

[mlopezFC]

One idea that pops into my mind, is that maybe we could leverage the menu generation to AppLayout.
Maybe we could build a new version (v4 or v5?) of that addon with the following features:

• Use the new webcomponents
• Maintain the old API and old way of using it, so migration from previous version could be easy
• Provide a clientCallable or fusion endpoint to provide server side items to a almost stand alone client side version (the new way of using it)