[Tooltip] Meet dismissable WCAG criterion

[eps1lon]

Closes #17279

Meets "dismissable" in WCAG 2.1 1.4.13:

A mechanism is available to dismiss the additional content without moving pointer hover or keyboard focus, unless the additional content communicates an input error or does not obscure or replace other content;

by listening to a global "Escape" keydown. This is similar to SCR39.

Follow-up:
To fully meet 1.4.13 we have to work on "hoverable" first which should also be explained in the docs.

[mui-pr-bot]

@material-ui/core: parsed: +0.06% , gzip: +0.12%
@material-ui/lab: parsed: +0.09% , gzip: +0.16%

Details of bundle changes

Generated by 🚫 dangerJS against 7818302

[oliviertassinari]

arrow function as in the other places (for nested scopes)?

[eps1lon]

(for nested scopes)

What does this mean?

[oliviertassinari]

I thought we were following named function for top-level scope and arrow function for nested levels, following pros and cons of https://stackoverflow.com/questions/34361379/are-arrow-functions-and-functions-equivalent-exchangeable

Suggested change

	function handleKeyDown(nativeEvent) {
	const handleKeyDown = (nativeEvent) =>

[eps1lon]

Does it matter? They end up as function anyway.

[oliviertassinari]

I have just realized that a native <div title="foo" /> behaves like the proposed changes on macOS 👍.

[eps1lon]

I have just realized that a native <div title="foo" /> behaves like the proposed changes on macOS .

Fun fact: The native title not being dismissable wouldn't violate that success criterion 🤷‍♂️ I wonder which corporate representative got that in so that their page is not liable.