Implement a DCAT-AP converter using RDF

[jahow]

Description

This PR introduces a new metadata converter for the DCAT-AP profile. The Metadata Converter app has been modified to allow handling this new format.

Limitations:

• writing to DCAT-AP is very limited for now
• reading is limited to certain fields of the model (i.e. no extents, no licence/constraints, etc.)
• Certain fields of the model are not read yet

Note that the converter can handle either RDF/XML, JSON-LD or Turtle (both for input and output).

This also fixes a bug where the original XML of a record was lost when it was modified and saved!

Architectural changes

Added DcatApConverter class in libs/api/metadata-converter

Screenshots

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

[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, common-domain, common-fixtures, ui-elements, feature-notifications, ui-catalog, util-shared, ui-widgets, ui-inputs, ui-layout, ui-map, ui-dataviz, database-dump, data-access-datafeeder, util-data-fetcher, util-app-config, data-access-gn4, util-i18n,
Affected apps: metadata-converter, metadata-editor, datahub, demo, webcomponents, map-viewer, search, datafeeder, data-platform,

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

[github-actions]

📷 Screenshots are here!

[coveralls]

coverage: 83.986% (+1.8%) from 82.189%
when pulling 4219ecc on semantic-converter
into e5f8e61 on main.

[tkohr]

Thanks for the big work @jahow ! Code LGTM as far as I can see.

When doing some quick testing with https://github.com/w3c/dxwg/blob/gh-pages/dcat/examples/basic-example.jsonld or ttl in the converter app I get errors when I switch to the ISO formats.

Error for ttl: Failed: Could not determine role code from role: pointOfContact
Error for jsonId: Failed: Invalid time value

[tkohr]

We should probably add jsonId and ttl here now.

[jahow]

Thank you for trying things out! I'll look into it

[jahow]

@tkohr I've addressed your comments, some mandatory fields of a record were indeed not filled with the DCAT-AP converter. I also tweaked the DCAT output so that it can sort of work with the GN DCAT-AP plugin :)

[tkohr]

Thanks, the conversion of the jsonld file above now works in the converter. Still getting an error for the same example in ttl though: status.component.ts:90 TypeError: Cannot read properties of undefined (reading 'name') at write-parts.ts:222:39. Watch out the CI also turned red.