HPCC-11072 Add total time for roxie and hthor

The existing code calculates "Total thor time" by adding
all of graph times togethor. Similar to "Total thor time",
in this fix, "Total roxie time" is added for roxie and
"Total hthor time" is added for hthor.

Signed-off-by: wangkx <kevin.wang@lexisnexis.com>