feat(profiler): trace filter state persistence

[gilles-g]

Summary

Opt-in persistence of the filter state (12.3): filter_persistence makes
$form->handleRequest($request) remember what was submitted and restore it on requests
carrying no filter data. Off by default, no public signature changed.

$form = $this->createForm(ItemFilterType::class, null, [
    'filter_persistence' => true,
    'csrf_protection' => false,
]);
$form->handleRequest($request);

Contents

- FilterState — holds the view data (strings/arrays only), restores via $form->submit().
- FilterStateStorageInterface — SessionFilterStateStorage (default), NullFilterStateStorage.
- FilterStateRequestHandler — stores a valid submission, restores, drops an invalid restoration,
  honours _reset (persistence.reset_parameter).
- FilterStateTypeExtension — declares the option, installs the handler.
- FilterUrlGenerator — permalinks.
- TraceableFilterStateStorage — profiler Persistence section in debug.

Review points

- No session is ever started: no previous session or stateless route ⇒ no persistence.
  Keeps anonymous listings cookie-free and cacheable.
- CSRF must be off on a persisted form (a token can't be replayed) — LogicException otherwise.
- The tracer reads the state back after writing: a storage that kept nothing shows not_stored,
  never saved. It decorates the interface alias, so custom storages are traced too.
- symfony/http-foundation + symfony/routing move to require (already transitive);
  symfony/security-csrf to require-dev.

[gilles-g]

@alioguz Hi,

if you want to have a look or test the feature. I admit the code was made with claude ;)