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.
{
        if (!block_out_stream)
        {
            /// Ignore all results when fuzzing as they can be huge.
            if (query_fuzzer_runs)
            {
                block_out_stream = std::make_shared<NullBlockOutputStream>(block);
                return;
            }
            WriteBuffer * out_buf = nullptr;
            String pager = config().getString("pager", "");
            if (!pager.empty())
            {
                signal(SIGPIPE, SIG_IGN);
                pager_cmd = ShellCommand::execute(pager, true);
                out_buf = &pager_cmd->in;
            }
            else
            {
                out_buf = &std_out;
            }
            String current_format = format;
            /// The query can specify output format or output file.
            /// FIXME: try to prettify this cast using `as<>()`
            if (const auto * query_with_output = dynamic_cast<const ASTQueryWithOutput *>(parsed_query.get()))