Small changes for CSV creation

CSV Creation should now work correctly for all files

_File:
- If an attribute is parsed and nothing is found, we put in a
placeholder. Changed the placeholder from “N/A” to “NA”

FieldTest_File:
- small formatting changes
- get_csvExtraValues now returns an array of 3 “NA”s, rather than an
empty array
- when getting 1 second UDP tests for get_csvUDPValues, added one more
field to check (Test Interval), just in case,