Reimplement vocab home using Bootstrap Grid instead of tables

[osma]

Reasons for creating this PR

The vocabulary home page looks ugly and is using twig template structures copied from Skosmos 2, for example HTML tables. This PR reimplements the main part and the download links using Bootstrap Grid, similar to the concept page.

Also contains a minor fix to the concept page. The template code is now aligned between these two so that partial page loads work better.

Link to relevant issue(s), if any

• part of Vocabulary Home twig-templates #1482

Description of the changes in this PR

• reimplement vocab info twig template using Bootstrap Grid (+ corresponding CSS changes)
• align concept and vocab home template structure

Known problems or uncertainties in this PR

• property-specific Cypress tests needed; but these are difficult to do because of the simplistic way that the backend provides vocab info properties as a key-value lists

Checklist

• phpUnit tests pass locally with my changes
• I have added tests that show that the new code works, or tests are not relevant for this PR (e.g. only HTML/CSS changes)
• The PR doesn't reduce accessibility of the front-end code (e.g. tab focus, scaling to different resolutions, use of .sr-only class, color contrast)
• The PR doesn't introduce unintended code changes (e.g. empty lines or useless reindentation)

[sonarcloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

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

See analysis details on SonarCloud

[joelit]

LGTM! I unchecked one box from the corresponding issue, since the PR didn't implement the feature (show title only once, even if it is present twice).