As noted in serval comments doing this goes against the WC3 spec,
and breaks parsing then re-serializing URLs that contain percent
encoded data, that was not encoded using the same character set as
the serializer.
For example, previously if you had a URL like:
https:://foo.com/what%2F%2F (the path is what + '//' percent encoded)
Creating URL("https:://foo.com/what%2F%2F").serialize() would return:
https://foo.com/what//
Which is incorrect and not the same as the URL we passed. This is
because the re-serializing uses the PercentEncodeSet::Path which
does not include '/'.
Only doing the percent encoding in the setters fixes this, which
is required to navigate to Google Street View (which includes a
percent encoded URL in its URL).
Seems to fix#13477 too