HPCC-12311 Revise based on review

1) changed CJobQueueBase to implement IJobQueueConst;
2) renamed getLastDequeuedInfo to doGetLastDequeuedInfo(qd, );
3) defined getLastDequeuedInfo in CJobQueueConst to explicitly
pass in qdata to call to doGetLastDequeuedInfo
4) moved activeq to CJobQueue and use in overloaded definition
of getLastDequeuedInfo in call to doGetLastDequeuedInfo
5) moved sessionid to CJobQueue;
6) added queryClientRootIndex() to base and updated related calls;
7) added queryClientRootSession() to CJobQueue and updated related
calls;
8) replaced CJobQueueBase::findRank with doFindRank;
9) renamed getItem() to doGetItem() and defined a getItem() to
call doGetItem();
10) replaced 'CJobQueueBase::getHead' with doGetItem();
11) replaced 'CJobQueueBase::getItem' with doGetItem();
12) removed 'CJobQueueBase::' from CJobQueueBase::copyItemsImpl();
13) removed waiting(sQueueData &qd);
14) moved paused() and stopped() to IJobQueueConst.

Haven't made change for copyItemsAndState -- waiting for a reply.

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