When deleting inconsistent metadata, do not delete entire permissions.

### Is your proposal related to a problem?

When making certain changes to a table, hasura may throw an error due to the change rendering existing metadata inconsistent.
Hasura will then propose to delete the inconsistent metadata.

As a user, if I am deleting or renaming a column, and this happens, I would expect to only delete the reference to the column.

But hasura deletes the entire permission.

### Describe the solution you'd like

When renaming a column, rename references to it in metadata.
When deleting a column, delete references to it in metadata, without deleting entire permissions.