Fix [Datahub]: Map keyword link to key

[tkohr]

Description

The PR maps the ES keyword.link from allKeywords to gn-ui's Keyword.key, which we forgot in #811 I think. This is necessary to allow updating search (filters) using the key.

Quality Assurance Checklist

• Commit history is devoid of any merge commits and readable to facilitate reviews
• If new logic ⚙️ is introduced: unit tests were added
• If new user stories 🤏 are introduced: E2E tests were added
• If new UI components 🕹️ are introduced: corresponding stories in Storybook were created
• If breaking changes 🪚 are introduced: add the breaking change label
• If bugs 🐞 are fixed: add the backport <release branch> label
• The documentation website 📚 has received the love it deserves

This work is sponsored by MEL.

[github-actions]

Affected libs: api-metadata-converter, api-repository, feature-catalog, feature-record, feature-router, feature-editor, feature-search, feature-map, feature-dataviz, feature-auth, ui-search,
Affected apps: metadata-converter, metadata-editor, datahub, demo, webcomponents, search, map-viewer, datafeeder,

• 🚀 Build and deploy storybook and demo on GitHub Pages
• 📦 Build and push affected docker images

[github-actions]

📷 Screenshots are here!

[tkohr]

Wondering if it would make sense to rename Keyword.key to Keyword.uri. Are they always URIs?

[coveralls]

coverage: 83.615% (-1.5%) from 85.088%
when pulling c674335 on keyword-key
into cec60ff on main.

[cmoinier]

Tested and LGTM 👍 Thanks!