ARIA live regions not read out by screen readers

[64json]

Per https://developer.mozilla.org/en-US/docs/Web/Accessibility/ARIA/ARIA_Live_Regions,

Dynamically adding an element with an aria-live attribute or specialized role to the document also won't result in any announcement by assistive technologies (as, at that point, the browser/assistive technologies are not aware of the live region yet, so cannot monitor it for changes).

Now that we dynamically load the audification component, screen readers do not read out the live region.

EDIT: it still works fine on VoiceOver + Safari/Chrome. It needs to be tested on other combinations.

[64json]

Experimental branch with an initially-loaded and globally-shared live region: singleton-live-region