refactor: form binder object models support

[platosha]

Fixes #3436

[codecov]

Codecov Report

❌ Patch coverage is 96.84385% with 19 lines in your changes missing coverage. Please review.
✅ Project coverage is 86.72%. Comparing base (a46edfc) to head (8b880b9).

Files with missing lines	Patch %	Lines
packages/ts/lit-form/src/stringConverters.ts	82.35%	9 Missing ⚠️
packages/ts/lit-form/src/BinderNode.ts	95.65%	4 Missing and 2 partials ⚠️
packages/ts/models/src/m.ts	97.59%	2 Missing ⚠️
packages/ts/lit-form/src/StringConverter.ts	0.00%	1 Missing ⚠️
packages/ts/lit-form/src/Validation.ts	50.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3816      +/-   ##
==========================================
+ Coverage   86.33%   86.72%   +0.39%     
==========================================
  Files         123      129       +6     
  Lines        8474     8754     +280     
  Branches     1301     1350      +49     
==========================================
+ Hits         7316     7592     +276     
- Misses       1135     1139       +4     
  Partials       23       23              

Flag	Coverage Δ
unittests	86.72% <96.84%> (+0.39%)	⬆️

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[sonarqubecloud]

Quality Gate failed

Failed conditions
3 Security Hotspots
54.8% Duplication on New Code (required ≤ 3%)
D Reliability Rating on New Code (required ≥ A)

See analysis details on SonarQube Cloud

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[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you all sign our Contributor License Agreement before we can accept your contribution.
1 out of 2 committers have signed the CLA.

✅ platosha
❌ Lodin
_{You have signed the CLA already but the status is still pending? Let us recheck it.}

Addressed, the reviewer cannot accept.

[sonarqubecloud]

Quality Gate failed

Failed conditions
54.6% Duplication on New Code (required ≤ 3%)
D Reliability Rating on New Code (required ≥ A)

See analysis details on SonarQube Cloud

Catch issues before they fail your Quality Gate with our IDE extension SonarQube for IDE

[heruan]

I've completed an initial review of the changes. The new object model types and their reference implementations are clear, well documented, and thoroughly tested. Updates to existing logic and method signatures improve readability and semantics, and the use of deprecation notices preserver backwards compatibility where applicable.

There are a few Sonar issues worth addressing, as well as some previously unresolved review comments that still apply. Additionally, the branch currently has conflicts that need to be resolved, and some failing tests that should be investigated.