[O11y][AWS Redshift] Convert legacy metrics to new lens metric

## Description
Below are the three panels which need to be converted in new Lens metric

1.  Database connections
2.  CPU Utilization
3.  Percentage of storage used

## Related issues

- https://github.com/elastic/integrations/issues/6862

### Screenshot
![image](https://github.com/elastic/integrations/assets/89848966/ca50eb7b-8fdd-4320-9b7a-479b5a7a2747)
