When connector to external source is used and document is being copied within this connector the Copy function does not work correctly.

For the source document with content repository does:
1. asks connector for new document's ID for copy to be created
2. generates new ID for document's copy content without asking connector for it
3. uses generated ID to store content into external source
4. fails as ID is not found

CmisConnector fails with ObjectNotFound error
FileSystem fails with incorrect id format as it expects to get key with slashes.