* Fix wrong grouping in Twitter valid_url regex

* Add support for xmpp URIs

Fixes #9776

The difficult part is autolinking, because Twitter-text's extractor does
some pretty ad-hoc stuff to find things that “look like” URLs, and XMPP
URIs do not really match the assumptions of that lib, so it doesn't sound
wise to try to shoehorn it into the existing regex.

This is why I used a specific regex (very close, although slightly more
permissive than the RFC), and a specific scan function (a simplified version
of the generalized one from Twitter).

* Remove leading “xmpp:” from auto-linked text

Fix #9993
Fix #5654

Found via `codespell -q 3 --skip="./app/javascript/mastodon/locales,./config/locales"`

* Add dat:// and gopher:// to URL extractor

Fix #6072

* Fix comment indent

* Add dweb, ipfs, ipns, ssb

In cases where a URL has a trailing hyphen the FetchLinkCardService incorrectly removes the hyphen when it is parsed

The hyphen is not a reserved character in the URI spec https://tools.ietf.org/html/rfc3986#section-2.2

Limiting allowed characters in the last character of the URL is came from twitter-text, but underscore is allowed on there, and Mastodon before #4941.