fdo#73800 fix incorrect separator in function description in Calc

Depending on locale, the function description with arguments did
show incorrect separator(s) for functions with PAIRED_VAR_ARGS.

Reviewed-on: https://gerrit.libreoffice.org/8052
Reviewed-by: Kohei Yoshida <libreoffice@kohei.us>
Tested-by: Kohei Yoshida <libreoffice@kohei.us>
(cherry picked from commit f38aa72c1d8f9e535d2b5cefbb2af7f6f37b81a8)

Conflicts:
	sc/source/core/data/funcdesc.cxx

Change-Id: Ie493a77285360a099e5b07e8360ecb5c6c6c1aec
Reviewed-on: https://gerrit.libreoffice.org/8057
Tested-by: Kohei Yoshida <libreoffice@kohei.us>
Reviewed-by: Kohei Yoshida <libreoffice@kohei.us>