STRING * n support in StarBasic

[Norbert Thiebaud]

Hi Noel,

FYI, I have taken advantage of a week semi-offline to get rid of
String in the whole 'basic' module...

I will push that soon in a feature branch to solicit reviews...

Most of the changes are cosmetic(*)/trivial... a few places needed
some rework to accommodate the change in API/functionality between
String/OUString....

(*) There are more cosmetics changes than strictly needed... but that
is because I basically browsed most of the code in 'basic', and I
sub-consciously added braces and fixed indentations to be able to read
it comfortably.