SEO: long title on landing page (skosmos:serviceNameLong configuration setting)

[osma]

Reasons for creating this PR

This PR makes it possible to set a long name for the service using a new setting skosmos:serviceNameLong. This name will be used as the <title> (and related metadata elements important for SEO) on the landing page. The setting is multilingual, so it is possible to set different names for different UI languages. If not set, the value of the skosmos:serviceName setting is used as a fallback.

I also adjusted the BaseConfig.getLiteral() fallback mechanism in case there is no configuration value in the requested language. In that case it picked an arbitrary value that could be in any other language. I adjusted the mechanism so it only falls back to a value without a language tag, but not to another language which could be surprising.

There's also a small change to drop twitter:title metadata because it turns out it's completely redundant according to Twitter/X developer docs when we already have og:title.

Link to relevant issue(s), if any

• Part of Search Engine Optimization for Skosmos 3.0 #1533

Description of the changes in this PR

• add support for skosmos:serviceNameSetting in GlobalConfig
• adjust BaseConfig.getLiteral so it uses a better fallback mechanism for multilingual values
• PhpUnit tests for the above
• use the serviceNameLong value in the Twig template of the landing page
• drop use of twitter:title because it's redundant
• Cypress test for the above

Known problems or uncertainties in this PR

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)

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 70.62%. Comparing base (27ce825) to head (f2cc004).
Report is 37 commits behind head on main.

Additional details and impacted files

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+ Coverage     70.59%   70.62%   +0.02%     
- Complexity     1643     1645       +2     
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  Files            32       32              
  Lines          4316     4320       +4     
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+ Hits           3047     3051       +4     
  Misses         1269     1269              

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[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]

https://developer.x.com/en/docs/twitter-for-websites/cards/overview/markup#overview-of-all-twitter-card-tags

Now that we're getting rid of twitter:title in favour of og:title, we could also change twitter:card to og:type. I reckon the domain of og:type fits skosmos pages better than the domain of twitter:card.

[joelit]

Looks good to me!

I would use this PR (or make a new one) to also change twitter:card to og:type to make sure the SE crawler can parse the metadata in the future.

[osma]

I would use this PR (or make a new one) to also change twitter:card to og:type to make sure the SE crawler can parse the metadata in the future.

I think it's out of scope for this PR, which is about titles/names. But I added this to the checklist in the main issue: #1533 (comment)

Merging this as-is.