Import of Agents should handle "overwrite" Option correctly

Current Situation

The Import functionality does not handle the "overwrite" option consistently when importing Agent configurations. This results in different behavior for Standalone Agents and Cluster Agents.

• When importing an exported Agent configuration with the "overwrite" checkbox selected, then Subagents in the Cluster Agent will be updated and will be put to the "not synchronized" status.
  However, the Standalone Agent is not updated accordingly.

• When importing the same Agent configuration into the same environment without selecting the "overwrite" checkbox, then an error occurs due to a unique constraint violation in the database:

DBInvalidDataException: could not execute statement [ ORA-00001: unique constraint (C##JS7G.UNIQUE_IAI_A) violated ] [insert into INV_AGENT_INSTANCES ("AGENT_ID","AGENT_NAME","CERTIFICATE","CONTROLLER_ID","DEPLOYED","DISABLED","HIDDEN","IS_WATCHER","JAVA_VERSION","MODIFIED","ORDERING","OS_ID","PROCESS_LIMIT","STARTED_AT","TITLE","URI","VERSION","ID") values (?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?)]: 1 ORA-00001: unique constraint (C##JS7G.UNIQUE_IAI_A) violated

Desired Behavior

The Import functionality should apply consistent behavior for use of the "overwrite" option with both Standalone and Cluster Agents:

• When the "overwrite" option is selected during import, then updated (Sub)Agents should be put to the 'not synchronized' status if the URL or the process limit were changed.
• If the "overwrite" option is not selected during import of the same (Sub)Agent, then the import should be skipped to prevent the "unique constraint violation" error.