Move overflow menu to start of menubar

[rolfsmeds]

Describe your motivation

With the addition of vaadin/platform#5018, the order in which menu items are collapsed into the overflow menu can be reversed. This has no effect on the position of the overflow menu itself (which remains at the end of the bar). Depending on the items in the bar, and the context in which the menubar is used, it can be preferable to have the overflow menu at the start of the bar instead.

Describe the solution you'd like

An API for moving the overflow menu to the start of the bar.
Flow API could be something like MenuBar::setOverflowMenuAtStart(boolean)
WC property could be called something like overflow-at-start

Describe alternatives you've considered

Allowing the developer to create his own overflow menu item and/or designate any top-level menu item as the overflow menu, would serve the same purpose and be even more flexible, but probably much more difficult to implement.

Additional context

No response