HPCC-10929 Set file's ContentType in WsDFU/DFUQuery response

The 'kind' attribute of a logical file should be returned as ContentType
inside the WsDFU/DFUQuery response if: (1) ESP WsDFU Client is 1.24 or
newer; and (2) the file has the 'kind' attribute.

The 'IsKeyFile' should not be set if the WsDFU Client is 1.24 or newer.

Signed-off-by: Kevin Wang kevin.wang@lexisnexis.com