SvxCheckListBox/SvTreeList/ListBox position types nitpick

Change-Id: Id77f90189d7dffe660ae509f563ea8eb6deb1727
user selectable string conversion models, related fdo#37132 fdo#74622

Determines how to treat text when encountered as operand in an arithmetic
operation or as argument to a function that expects a number instead.

Selectable under Tools->Options->Calc->Formula "Detailed calculation settings"
"Custom" from "Conversion from text to number" are:

Generate #VALUE! error:         =1+"1" or =1+"x" give #VALUE!
Treat as zero:                  =1+"1" or =1+"x" give 1
Convert only unambiguous:       =1+"1" gives 2, but =1+"1.000" or =1+"x" give #VALUE!
Convert also locale dependent:  =1+"1.000" may be 2 or 1001 ... =1+"x" gives #VALUE!

For "Generate #VALUE! error" and "Treat as zero" the "Treat empty string as
zero" option follows these settings, for "Convert only unambiguous" and
"Convert also locale dependent" it can be set independently.

When reading documents created by other spreadsheet applications or older
versions of LibreOffice, and to interchange documents between different locales
the "Convert only unambiguous" with "Treat empty string as zero = True" setting
is recommended, though LibreOffice so far acted as "Convert also locale
dependent" with "Treat empty string as zero = False", which is the reason that
option is kept as default.

The best setting to create new documents that can be interpreted by all
spreadsheet applications without on-the-fly string conversion is
"Generate #VALUE! error". Not having to convert strings during
calculation ist also faster, of course.

Change-Id: Ie6dc34a00a82064a2d862b2178ce715fab945f85
unit test for string conversion feature, related fdo#37132 fdo#74622

Change-Id: If7d9c032d6025a6c6bf850e338923296ba2590dd