bug#33870: 27.0.50; xref-goto-xref not configurable

[Juri Linkov]

X-Debbugs-CC: Dmitry Gutov <dgutov@yandex.ru>

There is no more need to replace switch-to-buffer with
pop-to-buffer-same-window in xref--pop-to-location
like was asked in https://debbugs.gnu.org/32790#206
because now a new option switch-to-buffer-obey-display-actions
can be customized to t.

But still there is one xref command, namely `xref-goto-xref' bound to
RET in the *xref* buffer that always displays the buffer in the
predefined window, and there is no way to change this behavior.

Is it possible to change it to use either pop-to-buffer-same-window
or at least switch-to-buffer?