HPCC-11999 Set url param for downloading WU Archive ECLXML

For WU Archive ECLXML file, the file type is 'xml'. The
logsWidget should set the url param for file dowmload using
the file type.

Signed-off-by: wangkx <kevin.wang@lexisnexis.com>
HPCC-11999 Should not set url param if not downloading

Signed-off-by: wangkx <kevin.wang@lexisnexis.com>
Merge pull request #6453 from wangkx/h11999

HPCC-11999 Set url param for downloading WU Archive ECLXML

Reviewed-By: Gordon Smith <gordon.smith@lexisnexis.com>
Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>