HPCC-10049 Retrieve data for displaying cumulative Roxie graphs

This fix adds the code to allow the existing WsWorkunits/WUGetGraph method
to retrieve data for displaying cumulative Roxie graphs. Two new input
parameters (target and query id) have been added to the method. If the
parameters are set, the method calls control:queryStats to get the data
for displaying cumulative Roxie graphs. If they are not set, the method
uses the exist code to get the data for ECL WU graphs.

And two small fixes: a. a compiling warning; b. a better time out for using
control:getQueryXrefInfo.

Signed-off-by: Kevin Wang kevin.wang@lexisnexis.com