Add `browse-url-qutebrowser'

Add `browse-url-qutebrowser'

The browser launcher supports the NEW-WINDOW argument and
`browse-url-qutebrowser-new-window-is-tab' to open tabs.
Furthermore opening new URLs is sped up via Unix socket IPC if
available.
* lisp/net/browse-url.el (browse-url-qutebrowser-send): Function
to send command to Qutebrowser via IPC.
(browse-url-qutebrowser): New browser launcher.  Use
`browse-url-qutebrowser-send'.
(browse-url-qutebrowser-program, browse-url-qutebrowser-arguments)
(browse-url-qutebrowser-new-window-is-tab): New customizables.
(browse-url-mozilla-new-window-is-tab)
(browse-url-firefox-new-window-is-tab)
(browse-url-epiphany-new-window-is-tab): Improve docstrings.

* etc/NEWS: Announce the change.
(Bug#74781)

(cherry picked from commit ed1f3b8488e18143d658e4f1aca8d21a3b84e2b2)