[verifier] Add 'control_query_utf8' and 'test_query_utf8' columns.

[spershin]

Description

Add 'control_query_utf8' and 'test_query_utf8' columns to the verifier query table.

Motivation and Context

We realized that existing 'control_query' and 'test_query' columns are of latin1 format, which results is some utf8 characters loss. Direct conversion of the table columns is failing due to the existing data, so we have come up with a workaround via the additional temporary columns. At some point we can remove either the new columns or the old ones and keep the new ones.

The new columns are used if not null, otherwise the old ones are used.

Test Plan

Made a custom build and tested it on a altered table. Works like a charm!

== NO RELEASE NOTE ==