feat: add generic single valued signal (ValueSignal)

[taefi]

Description

Fixes #2623

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

Attention: Patch coverage is 78.57143% with 9 lines in your changes missing coverage. Please review.

Project coverage is 92.10%. Comparing base (5686f0b) to head (08af17a).
Report is 4 commits behind head on main.

Files with missing lines	Patch %	Lines
packages/ts/react-signals/src/polyfills.ts	0.00%	6 Missing ⚠️
packages/ts/react-signals/src/ValueSignal.ts	90.90%	2 Missing ⚠️
packages/ts/react-signals/src/FullStackSignal.ts	88.88%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2672      +/-   ##
==========================================
- Coverage   92.33%   92.10%   -0.23%     
==========================================
  Files          76       79       +3     
  Lines        2492     2521      +29     
  Branches      646      652       +6     
==========================================
+ Hits         2301     2322      +21     
- Misses        144      152       +8     
  Partials       47       47              

Flag	Coverage Δ
unittests	92.10% <78.57%> (-0.23%)	⬇️

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[platosha]

LGTM overall. Please mind the TypeScript error in the tests, makes the build red.

[sonarcloud]

Quality Gate failed

Failed conditions
5.6% Duplication on New Code (required ≤ 3%)

See analysis details on SonarCloud

[taefi]

LGTM overall. Please mind the TypeScript error in the tests, makes the build red.

Thanks, for the review. Done.

[vaadin-bot]

This ticket/PR has been released with Hilla 24.5.0.alpha13 and is also targeting the upcoming stable 24.5.0 version.