Remove use of ICU C++ NumberFormat class

Remove use of ICU C++ NumberFormat class

This change removes NumberFormat in favor of UNumberFormat. There is a
bit of work that needs to happen in order to keep the normalization code
we use to convert an ICU pattern so to something we can match against
working.

Instead of UnicodeStrings, the input to the normalization function is
now a UChar* and we build up a std::string during normalization.  This
allows us to also skip a conversion from UChar* back to char* so we can
find the correct pattern in our collection of patterns to examine.