feat: add automatic subscribe/unsubscribe to signals

[taefi]

Description

Fixes #2621

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.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 92.21%. Comparing base (0539d03) to head (34f3e96).
Report is 6 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2663      +/-   ##
==========================================
+ Coverage   92.16%   92.21%   +0.05%     
==========================================
  Files          76       76              
  Lines        2449     2466      +17     
  Branches      636      639       +3     
==========================================
+ Hits         2257     2274      +17     
  Misses        144      144              
  Partials       48       48              

Flag	Coverage Δ
unittests	92.21% <100.00%> (+0.05%)	⬆️

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[sonarcloud]

Quality Gate passed

Issues
1 New issue
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 Hilla 24.5.0.alpha10 and is also targeting the upcoming stable 24.5.0 version.