Replace the stopgap type sal_uLong as SvNumberFormatter
format index uses sal_uInt32.

SwInsertDBColAutoPilot uses format indices from SvNumberFormatter and
from the property "FormatKey" which is stored as sal_Int32 but ctor
guards against negative values.

Change type of loop variable in SwCaptionDialog to avoid narrowing
in GetFormatStr/GetFormatKey.

Change-Id: I79980696c07760f7ff026bb1bacf0e069363898c
Reviewed-on: https://gerrit.libreoffice.org/40464Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>