Clean up toolbar deprecations

[axelboc]

Since #1652 has a breaking change, I go ahead and remove some deprecated components, as well as the obsolete align prop of ExportMenu. I also re-use the generic Btn component in ExportMenu, InteractionHelp and OverflowMenu and fix a small ARIA bug.

BREAKING

• Remove deprecated components GridToggler and FlipYAxisToggler — use ToggleBtn directly instead.
• [ExportMenu] Remove prop align — the popup now remains within the bounds of the viewport automatically, thanks to Floating UI.
• [Btn] Prop onClick now receives the MouseEvent as first parameter, so make sure you don't pass a state setter as is, like onClick={toggleOpen}.

NEW FEATURE

• [Btn] Add prop withArrow to display a drop-down arrow.
• [Btn] Forward ref.
• [Btn] Allow forwarding any valid attributes to the button element (HTMLAttributes<HTMLButtonElement>)