Clarify "Deleting a database cannot be undone" for Cloud Dedicated / Clustered

The database deletion docs for influxctl and Explorer UI both state that "Deleting a database cannot be undone". This is not true now for Cloud Dedicated and Clustered, since databases can be undeleted within the soft delete grace period (currently 7 days for Cloud Dedicated). The table deletion docs do not have any similar verbiage.

Both database deletion and table deletion should be updated to mention that the resources can be undeleted within the soft delete grace period. This grace period is defined internally and may change, so it's probably best for the docs to not specify the grace period at this time.

Databases and tables can't be undeleted in Core and Enterprise AFAIK, so I'm not sure how best to approach the Explorer UI docs.

##### Relevant URLs
- https://docs.influxdata.com/influxdb3/cloud-dedicated/reference/cli/influxctl/database/delete/
- https://docs.influxdata.com/influxdb3/cloud-dedicated/reference/cli/influxctl/table/delete/
- https://docs.influxdata.com/influxdb3/explorer/manage-databases/#delete-a-database