Fix issue with predicate filtering to extract decisions

[elpoelma]

Overview

This PR includes a fix to the code responsible for extracting decisions of a document. It takes into account that the rdf type predicate can be represented by 'a' as well as 'http://www.w3.org/1999/02/22-rdf-syntax-ns#type'.

connected issues and PRs:

None

Setup

Test this PR in combination with https://github.com/lblod/app-gelinkt-notuleren.

prepublish:
    environment:
      NODE_ENV: "development"
    volumes:
      - <path-to-this-service>:/app/

How to test/reproduce

• Start the application
• Login and create a new meeting with a new agendapoint
• Insert a decision in the agendapoint
• Open up the meeting publishing page and select 'Decision List'
• The decision list should correctly show up (the decisions should be found), no error should be shown.

Checks PR readiness

• UI: works on smaller screen sizes
• UI: feedback for any loading/error states
• Check cancel/go-back flows
• Check database state correct when deleting/updating (especially regarding relationships)
• changelog
• no new deprecations

[lagartoverde]

looks good, maybe we should look for more places where we have this not expanded predicates because we fixed a ton of similar bugs recently