fix: Add util method for detecting Hilla auto layout

[mshabarov]

Description

Adds a new util method that detects layout entries in file-routes.json.

Related-to vaadin/hilla#2825

Type of change

• Bugfix
• Feature

Checklist

• I have read the contribution guide: https://vaadin.com/docs/latest/guide/contributing/overview/
• I have added a description following the guideline.
• The issue is created in the corresponding repository and I have referenced it.
• I have added tests to ensure my change is effective and works as intended.
• New and existing tests are passing locally with my change.
• I have performed self-review and corrected misspellings.

Additional for Feature type of change

• Enhancement / new feature was discussed in a corresponding GitHub issue and Acceptance Criteria were created.

[github-actions]

Test Results

1 142 files  ± 0  1 142 suites  ±0   1h 24m 21s ⏱️ +20s
7 458 tests + 5  7 408 ✅ + 5  50 💤 ±0  0 ❌ ±0 
7 827 runs  +55  7 767 ✅ +55  60 💤 ±0  0 ❌ ±0 

Results for commit 6c9f777. ± Comparison against base commit b425bad.

♻️ This comment has been updated with latest results.

[mshabarov]

It's MenuRegistryTest's new code that impacts should_not_initialize_UI_and_add_initialUidl_when_invalid_route somehow.
I'm looking into it.

[mshabarov]

Or it's a file routes cache that is not cleaned.

[mshabarov]

Added a cache cleanup for the failed test.
I think in real projects or end-to-end tests this problem shouldn't happen, because file routes are not going to be changed during app running in production.

However, unit tests may suffer.

[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

[vaadin-bot]

This ticket/PR has been released with Vaadin 24.5.0.