Describe the bug

The relationship field does not remove the old plaintext Author value when you replace it with an entity in the DsDynamicLookupRelationModalComponent.

To Reproduce

Steps to reproduce the behavior:

1. Set orcid.api-url = https://pub.sandbox.orcid.org/v3.0 in your local.cfg (this way you can easily import new authors from ORCID)
2. Import/create a workspace item with some authors in a collection with entity type Publication (this way the author field will already be correctly set up)
3. Click on the lookup button next to one of the plain text authors
4. Select an author from the Local Authors tab or from the ORCID tab if you don't have any locally
5. Close the modal

Expected behavior

The new entity relationship should be created AND the old plain text value should be removed