HPCC-8888 Rename Spray CSV to Spray Variable in EclWatch display

The existing Spray CSV menu item may be used for spraying a variable
length file, including CSV file. This fix renames the Spray CSV menu
item to Spray Variable. It also renames several display items related
to the Spray CSV function, such as CsvSeparate, CsvEscape, etc. Those
items are displayed on DFU WU Details page and Logical File Details
page.

Signed-off-by: Kevin Wang <kevin.wang@lexisnexis.com>