HPCC-12425 Display 'Total Cluster Time' in ECLWatch UI

The existing ECLWatch displays the 'Total Thor Time' inside
both ECL Workunits page and ECL WU Details page. The 'total
cluster time' has been added for hthor and roxie. The timing
information, as well as the 'total thor time', should be
displayed under new name 'total cluster time' in both pages.

This fix includes both legacy ECLWatch and new ECLWatch. The
related code in legacy ECLWatch is also cleaned.

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