4GL: Implement $fieldinfo(FLD,"syntax")

4GL: Implement $fieldinfo(FLD,"syntax")

As a 4GL developer I need to access to the declarative values of field syntax,
specifically NED, so I can use this information to write my own Proc without
the need to duplicate the information first in e.g. #defines.

Details

Enhance Proc function $fieldinfo, so it also returns the declarative field
syntax values, specifically whether a field is NED.

Proc function $fieldinfo(FLD, "syntax") returns the value as it is defined in
the repository
The returned value is not affected by the Proc instructions fieldsyntax,
field_syntax, nor $fieldsyntax()
The function returns characteristics of the field, not necessarily the literal
entered string in the repository