Query Parameter Checking for Stats Queries should move from QE to OpServer

[Anish Mehta]

After we move Stats schema's out of viz.sandesh, QE will not have access to Stats Schema.
We should add Query Parameter checking to OpServer:

code from StatsSelect::StatsSelect() in QE:

            if (main_query->stats().is_stat_table_static()) {
                if (agg != QEOpServerProxy::COUNT) {
                    StatsQuery::column_t c = main_query->stats().get_column_desc(sfield);
                    if (sfield == g_viz_constants.STAT_TIME_FIELD) {
                        if (ts_period_ || isTBC_) {
                            QE_TRACE(DEBUG, "StatsSelect cannot aggregate " <<
                                sfield << "with T=");
                        }
                        isTC_ = true;
                    } else if (sfield == g_viz_constants.STAT_TIMEBIN_FIELD) {
                        if (isT_ || isTC_) {
                            QE_TRACE(DEBUG, "StatsSelect cannot aggregate " <<
                                sfield << " with T");
                        }
                        isTBC_ = true;
                    } else if (c.datatype == QEOpServerProxy::BLANK) {
                        QE_TRACE(DEBUG, "StatsSelect unknown field " << select_fields_[j]);
                        return;
                    }
                } else {
                    if (sfield != main_query->stats().attr()) {
                        QE_TRACE(DEBUG,"StatsSelect Invalid COUNT field " << sfield);
                        return;
                    }
                }
            }

[OpenContrail Admin (ci-admin-f)]

Review in progress for https://review.opencontrail.org/22535
Submitter: Nikhil Bansal (<email address hidden>)

[OpenContrail Admin (ci-admin-f)]

Reviewed: https://review.opencontrail.org/22535
Committed: http://github.org/Juniper/contrail-controller/commit/5019cad90723de1aebd1bbc9d4313e37923da27f
Submitter: Zuul
Branch: master

commit 5019cad90723de1aebd1bbc9d4313e37923da27f
Author: Nikhil B <email address hidden>
Date: Thu Jul 28 11:31:40 2016 +0530

move parameter validation for stats queries from QE to opserver

Now, with stats table schema removed from viz.sandesh, it is no longer
available to QE for parameter validation. These parameter validation steps
should instead be done in Opserver now.
Closes-Bug:1602130

Change-Id: I8d7eaa8fa9faa45de62715a6d002e0e6981fca9a