New Bangle.js 2 menu system

This is a hard one - as far as the menu system is concerned there is no difference between a menu item that does something and one that opens a menu - they are both items that are tapped. I guess we could try and have some kind of way of distinguishing them...

If you are happy for this to require a code change in apps, I will submit a PR for this. Unchanged apps would work but would show submenu without the ">" as it was in a previous iteration of the new system. I imagine this is OK, as apps need to change for the booleans anyway.

Edit: Actually, I think I can do it without requiring any change on the app side... I will report back.

Edit Edit: Ah, no, that was silly. Original offer stands.

Edit x 3 ( a longer one):

I can do it so it doesn't require any changes on the app side, but it feels a bit dirty...

My original idea was to change the way submenus are created to an object with the key submenu (the value would be the submenu itself). Standard menu items would be rendered without the ">" but if the item is a submenu, it is rendered with it. Existing code would work, but would not show the ">".

My hacky idea is to call .toString on the function in menu items and see if it contains E.showMenu. I think I would prefer not to do this, but existing apps can't be changed to use the { submenu: submenu} style until everyone has the new menu system (or can they?).