refactor: create Europeana APIs package

[rwd]

• create a new apis package which contains the Europeana API client code formerly in plugins/europeana
• keep those API client classes as minimal as possible, moving other helper functions out to either:
  • another new package, utils, for helper functions that may need to be used across packages; or
  • a new utils directory within the portal package for helper functions only it needs to use
• load API config from env by default
• decouple API config from nuxt context, delegating use of nuxt config in API config to europeana-apis plugin
• change the signature of the EuropeanaEntityApi#get method to expect Entity API type and ID
• move EuropeanaEntityApi#imageUrl to a new mixin, entityImageUrl
• move EuropeanaRecordApi#mediaProxyUrl to EuropeanaMediaProxyApi#url
• move Record API search method translation param handling into SearchInterface component
• move Record API search result reduction to search util function reduceFieldsForSearchResult

[github-actions]

JIRA ticket: EC-6758

[github-actions]

Preview deployment: https://pr-2325.portal-js.dev.eanadev.org/

[github-actions]

Style guide deployment: https://pr-2325.styleguide.dev.eanadev.org/

[sonarcloud]

Quality Gate passed

Issues
5 New issues
0 Accepted issues

Measures
0 Security Hotspots
92.8% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud