fdo#73617 sc: Don't update the gui during live preview

Apart from (apparently) being not necessary, it creates
bugs like this one. If the selection consist of multiple
fonts, it leads to clearing the font name box, which in
turn leads to scrolling the list up.

(cherry picked from commit 6ba8b7f5eacac969e4781d63718083a05491b1bc)

Conflicts:
	sc/source/ui/view/viewfunc.cxx

Change-Id: I8e702b9b4d4a1f7ad1ded5de1a5e162f039f6d4d
Reviewed-on: https://gerrit.libreoffice.org/12294
Reviewed-by: Kohei Yoshida <libreoffice@kohei.us>
Tested-by: Kohei Yoshida <libreoffice@kohei.us>