dashboard monitoring TPS should only show general TPS

[dbsid]

Bug Report

Please answer these questions before submitting your issue. Thanks!

What did you do?

On the dashboard, all transactions are displayed. By default, Grafana only shows business transactions, and internal TiDB transactions are not displayed. The inconsistency cause confusion.

What did you expect to see?

What did you see instead?

What version of TiDB Dashboard are you using (./tidb-dashboard --version)?

      category: 'transaction',
      metrics: [
        {
          title: 'Transaction Per Second',
          queries: [
            {
              promql:
                'sum(rate(tidb_session_transaction_duration_seconds_count[$__rate_interval])) by (type, txn_mode)',
              name: '{type}-{txn_mode}',
              type: 'line'
            }
          ],
          nullValue: TransformNullValue.AS_ZERO,
          unit: 'short'
        },