Fix #5519: Authors with invalid Authority entries not displayed properly

[guillermo-escire]

References

Fixes #5519

Description

Authors with invalid Authority entries were appearing smashed together on Item pages. This fix ensures proper separation between authors regardless of whether they have a valid or invalid Authority value.

Instructions for Reviewers

Instructions for Reviewers
List of changes in this PR:

• metadata-representation-list.component.html — Added separator
  between each ds-metadata-representation-loader in the @for loop so authors are always visually separated.
• metadata-link-view.component.ts — Changed entityType: 'PRIVATE' to entityType: null in the else branch of createMetadataView, so authors with an invalid authority are rendered as plain text instead of triggering the textWithIcon template.
• metadata-link-view.component.html — Moved d-inline-block div inside the @if (metadataView) block so no empty div is rendered when metadataView is null.
• metadata-link-view.component.spec.ts — Updated existing test when item is not found to expect textWithoutIcon instead of textWithIcon, reflecting the corrected behavior.
• metadata-representation-list.component.spec.ts — Added test to verify that separators are rendered between ds-metadata-representation-loader components.

How to test:

1. Find an Item with multiple authors in dc.contributor.author
2. Go to Administer → Metadata tab
3. Add a fake UUID like 94466ca9-b8d2-4c8e-9898-3ae87be9b116 in the Authority column for each author
4. Save and go back to the Item page
5. Authors should appear separated on individual lines, not smashed together

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