feat(tooltip): show tooltip on longpress; remove delay on mouseleave

[andrewseguin]

Support longpress for mobile users to see tooltips. Adheres better to the md spec which says that "On lift" there should be a delay, which was incorrectly applied to mouseover.

Partially addresses #1808 by hiding the tooltip immediately when the mouse is hidden.

[KostyaTretyak]

Also probably need to change the positioning tooltip. Now, when the tooltip is displayed and when the scroll page, tooltip remains fixed.

[fxck]

@KostyaTretyak it's an overlay related problem, very annoying one though, happens to all components using overlay, like menu.

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