VLOOKUP fix

[Kohei Yoshida]

Hi there,

I'd like to request an expedited backport of one recent fix of mine to
4.2 and 4.2.1.

https://gerrit.libreoffice.org/8042
https://gerrit.libreoffice.org/8043

This change fixes

https://bugs.freedesktop.org/show_bug.cgi?id=72348
https://bugs.freedesktop.org/show_bug.cgi?id=74558

and potentially others (reported or unreported) that uses the same
BinarySearch() method which was unfortunately not functional after the
calc core storage change.

The change is large, but we need this change in order to bring the
algorithm used there back to the old one in 4.1.  IMO it's better to get
this one in and deal with whatever corner cases that may be affected by
this (if any), than leaving the current one there which we cannot tweak
to fix any bugs caused by it.  And we should get this one in sooner
rather than later.

Thanks,

Kohei