Disable rdfaAware setting on heading nodes

[elpoelma]

Overview

This PR disables the rdfaAware setting on heading nodes for two main reasons:

• To ensure consistency with https://github.com/lblod/frontend-reglementaire-bijlage
• The rdfaAware setting never really worked very well in combination with heading nodes. Typically (IMO) it's not a good idea to mix markup/styled nodes (e.g. headings, paragraphs) with data nodes (block_rdfa, inline_rdfa...)

connected issues and PRs:

lblod/frontend-reglementaire-bijlage#291

How to test/reproduce

• Start the frontend
• Open any agendapoint/regulatory statement/intro,outro
• Notice that the heading nodes are no longer rdfa-aware: you can easily enter inside of them for example, no border around them...
• Check if the copy function still works as expected

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
• npm lint
• no new deprecations