Duplicate tags fails the import after upgrade from 4.0 to >=5.4

The issue was found in LLD Item Prototypes.
If an Item Prototype has an Application and an Application Prototype of the same name, two Tags are created with the same attributes during the upgrade.

When the Template is exported/imported from one environment to another, the Import process fails with an error saying that the tag already exists.

It would be correct to modify the update process to check for potential duplicates before adding the second tag.