feat(badge): Badge should warn when used on an `aria-hidden` `mat-icon`

[jelbourn]

Feature Description

From usages across Google, we've seen that's it's common for devs to put matBadge on <mat-icon>. The problem is that <mat-icon> is aria-hidden by default, meaning that the badge content is also invisible to screen readers. Our documentation already calls this out as a misuse of the badge, but we can go a step further and actually produce a console warning. This would look something roughly like

if (ngDevMode && host.nodeName === 'mat-icon' && host.getAttribute('aria-hidden') === 'true') {
  console.warn('Warning: detected matBadge on a "<mat-icon>" with "aria-hidden="true"\n${host.outerHTML}');
}

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