Fixing inconsistent prev/next navigation buttons

[olemartinorg]

Description

Ancient description, copy-pasted:

I've observed that the previous/next navigation buttons sometimes mysteriously disappeared, and I was about to create a bug report for it. However, to figure out if it was just my config that was wrong, I looked into it and quickly found the cause behind the problem - these buttons seem to somewhat rely on a navigation property set in the layout file (which is an undocumented feature?!). I'm a bit confused about what was supposed to happen here, so I'm opening a draft PR to get some feedback. These changes seems to work in the same way the documentation describes, though.

Now that main is targeting v4, this should be merged into main and the next branch closed.

Related Issue(s)

• Fixing inconsistent prev/next navigation buttons #657
• Fixing inconsistent prev/next navigation buttons #737

Verification/QA

• Manual functionality testing
  • I have tested these changes manually
  • Creator of the original issue (or service owner) has been contacted for manual testing (or will be contacted when released in alpha)
  • No testing done/necessary
• Automated tests
  • Unit test(s) have been added/updated
  • Cypress E2E test(s) have been added/updated
  • No automatic tests are needed here (no functional changes/additions)
  • I want someone to help me make some tests
• UU/WCAG (follow these guidelines until we have our own)
  • I have tested with a screen reader/keyboard navigation/automated wcag validator
  • No testing done/necessary (no DOM/visual changes)
  • I want someone to help me perform accessibility testing
• User documentation @ altinn-studio-docs
  • Has been added/updated
  • No functionality has been changed/added, so no documentation is needed
  • I will do that later/have created an issue
• Support in Altinn Studio
  • Issue(s) created for support in Studio
  • This change/feature does not require any changes to Altinn Studio
• Sprint board
  • The original issue (or this PR itself) has been added to the Team Apps project and to the current sprint board
  • I don't have permissions to do that, please help me out
• Labels
  • I have added a kind/* label to this PR for proper release notes grouping
  • I don't have permissions to add labels, please help me out

[sonarqubecloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
2 Code Smells

91.7% Coverage
0.0% Duplication