wpWidgets.l10n.widgetAdded string was unintentionally removed in 5.0 causing js error

[garrett-eclipse]

Hello,

When you use the 'Add Widget' button to introduce a widget to the sidebar it throws a javascript error;

a11y.min.js?ver=2.5.1:formatted:102 Uncaught TypeError: Cannot read property 'replace' of undefined
    at l (a11y.min.js?ver=2.5.1:formatted:102)
    at Module.c (a11y.min.js?ver=2.5.1:formatted:124)
    at widgets.min.js?ver=5.3.3-alpha-47319:formatted:341

This is caused by the widgetAdded string being missing from the wpWidgets.l10n array, this string is used for the a11y speak function but since it was accidentally removed in [44163] for #45145 an error is now thrown.

Patch incoming.

[garrett-eclipse]

Reintroduces the widgetAdded string to avoid throwing a a11y speak error.

[garrett-eclipse]

In 49505.diff I've reintroduced the string for widgetAdded to avoid the a11y speak error.

[audrasjb]

Hi @garrett-eclipse,

I can reproduce the issue.
The patch works, moving to next release :)

Thanks!
Jb

[SergeyBiryukov]

In 47353:

Accessibility: Widgets: Restore missing string in script loader.

The string was previously added in [42794] and accidentally removed in [44163].

Props garrett-eclipse, audrasjb.
Fixes #49505.