Connector cache timeout unaware of exports causing LDAP errors

The connector cache ConnectorEngineConnectorCache doesn't refresh the timeout when a connector is used for export.

Observation

Modify anchor operations would fail if a state was kept on the connector and used between the modify anchor call and the update entities call. Failures occurred every 1 minute, which is the timeout for the cache expiry.

Task

Clean up ConnectorEngineConnectorCache, as it's not clear how it works. Replace it with DictionaryCache if possible as the caching logic is handled for us. May need to subscribe to events for export and then Touch the connector so that the timeout doesn't expire. Ensure that unit tests are updated.