fdo#48729 Change int16->int32 in auto replace dialog.

Auto correct / replace dialog supported only 65535 (2^16) entries
(per language) due to using sal_uInt16 in the code. This restriction
existed only because of legacy code which was meanwhile refactored to
use dynamic containers (like std::set, std::vector).
This fix changes usage of sal_uInt16 to sal_uInt32 to increase the
number of entries to a much higher value.

Change-Id: Ica77648915266fed67602a4e30b59a4e55e34efc