Add an option for `clickhouse-client` with a list of tests for extensive fuzzing.
Processing of these tests will be interleaved between every other tests, so we will get much better fuzzing coverage.
// file.
            if (test_hint.echoQueri
                echo_queries = true;
        }
        /// Several queries separated by ';'.
         of line, not ';'.
        /// An exception is VALUES format where we also support semicolon in
        /// addition to end of line.
        const l_queries_text.data();
        const char * all_queries_end = all_queries_text.data() + all_queries_text.size();
        while (this_query_begin < all_queries_end)
        {
            // Use the token iterator to skip any whitespace, semicolons and
            // comments at the beginning of the query. An example from regression
            // tests:
            //      insert into taues ('invalid'); -- { serverError 469 }
            //      select 1
            // Here the tesets parsed as a part of second query.
            // We parse the `INSERT VALUES` up to the semicolon, and the rest
            // looks like a two-line query:
            
            //      select 1
            // and we expech error 469, but this hint is actually
            // for the previous query. Test hints should go after the query, so
            // we can fix this by skipping leading comments. Token iterator skips
            // comments and whitespace by itself, so we only have to check for
            // semicolons.
            // The code block isibility of `tokens` because we have
            // another such variable further down the code, and get warnings for
            // that.