Add option to make specific links truncated with ellipses and others not truncated

[seankwilliams]

1787b6a changed links inside footnotes so that they are truncated by an ellipses if there isn't a clear wrap position and they would extend beyond the tooltip. However, a user at https://wordpress.org/support/topic/truncated-text-2/ is reporting that the link is truncating when they don't want it to. We're going to need a way to support both use cases: when links are too long and need to be truncated, and when links should wrap and display inline with the text as normal.

I'm not sure the best way to approach this, but options include fixing this just with CSS that's smart enough to handle both cases (not sure it's possible), specific attributes for individual footnote shortcodes, or a site-wide setting.

[seankwilliams]

Suggestion from the WordPress topic: if the link text is a URL, truncate it. If it's just words, don't.

Not sure the best way to implement that, but it's an idea to consider when working on this issue.