Issues with multiple submenus with same id

[Lynesth]

We currently can add multiple submenus with the same "id"
Example:

$menu = (new CliMenuBuilder)
    ->addSubMenu('Options')
        ->addItem(...)
        ->end()
    ->addSubMenu('Options')
        ->addItem(...)
        ->end()
    ->end()

Both of them work but only the second one has its parent set and can "Go Back" to the main menu.

We either need to prevent adding a menu with the same ID or, even better, handle it differently (maybe like the uniqid that's used with split items ?).

[AydinHassan]

uniqid sounds good to me!

[AydinHassan]

This turns out to be more complicated - If we allow multiple sub menus with the same name then CliMenuBuilder#getSubMenu() will not function correctly either.

We can't just add a uniqid id on because the user needs to be able to reference it. Not sure what to do here.

[AydinHassan]

Should be fixed by #155