Symfony version(s) affected: 5.0.7 (all versions since #11601)

Description
Special characters in HTTP Basic Auth passwords in an URL need to be url-encoded.

Example: foo@bar becomes foo%40bar, in an URL: http://user:foo%40bar@example.org

The UrlValidator does not allow percent signs in username and password.

Possible Solution
Allow % in username and password part of UrlValidator regex.