Job Stream Import should provide overwrite and merge option

Current Situation

When importing a job stream to an existing folder then parts of the job stream may already exist in other folders. The new imported job stream will be merged with these parts in other folders. There is no hint that already parts of the job stream do exist and that a merge is performed.

Desired Behavior

When importing a job stream it should be visible whether already parts of the job stream do exist in other folders or in the same folder.

If so, the user should have the option to

1. merge the new part of the job stream with other parts in other folders:
   • this operation is the current behavior.
2. create a new job stream that is not part of the other job stream in other folders:
   • this operation will import the job stream with a new name that does not yet exist.
3. overwrite an existing job stream in the same folder:
   • this operation is the current behavior.