Fix discrepency in provenance after renaming portal entities

[tschaffter]

Background: Provenance currently tracks the title of entities. This is likely performed to make the generation of provenance graph easier.

Issue: Duplicating information about the title of an entity (in the portal and in provenance) leads to a discrepancy when the user rename an entity in portal as its title is not updated in provenance.

Suggested solution: Do not save the title in provenance, only the object ID of an entity. This eliminates the risk of discrepancy in the entity title. The rendering of the provenance graph would need to be updated to grab the title of the entities from the portal DB.

Alternative solution: Make a call to provenance to update the title of the entity each time it is renamed. The risk of introducing discrepancy remain as the title information is duplicated.