Group common code for csv generation and simplify OUString handling
Group common code for csv generation and simplify OUString handling

Though writing data incrementally without building the whole line would
be more efficient.

Change-Id: I396378c6f306f4ff0d10037f87c33005b7e4b640

JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core