Add language specific UUID URLs

[bastianallgeier]

This PR …

This is an attempt to finally get parts of the multi-language UUID issues solved. (#5551)

This adds a new route for language-specific UUID urls:

Examples:

/en/@/page/1234
/en/@/file/1234

Docs

Ready?

• In-code documentation (wherever needed)
• Unit tests for fixed bug/feature
• Tests and checks all pass

For review team

• Add lab and/or sandbox examples (wherever helpful)
• Add changes & docs to release notes draft in Notion

[distantnative]

Either we should add unit tests or we should be more explicit what we want to ignore for coverage.

[bastianallgeier]

@distantnative I'm trying to create tests for the UUID route but I fail to setup a test environment with working UUIDs. Could you maybe have a look at the test? Why can the model not be found like that?

[distantnative]

Had you tried manually adding a uuid in the app setup ['content' => ['uuid' => 'my-uuid']]? That's how many of the other tests do it.

[bastianallgeier]

Yep, I tried that too but also without luck.

[distantnative]

@bastianallgeier Ok I finally understood where it fails:

• The uuid route looks up the model lazily, so only from cache. Since the cache is not populated, it fails
• When I was trying to manually set a UUID, I did it with content. But we are in multilang territory, so we have to set the translations array instead

Alternatively, solving #5181 too.