[Reflection] Add ClassReflectionProvider facade over PHPStan ReflectionProvider

[TomasVotruba]

First step of lowering direct phpstan/phpstan coupling, while keeping all rules running on PHPStan's reflection underneath.

What

Class lookups now go through a narrow Rector-owned facade instead of PHPStan\Reflection\ReflectionProvider:

namespace Rector\Reflection;

final readonly class ClassReflectionProvider
{
    public function __construct(
        private ReflectionProvider $reflectionProvider,
    ) {
    }

    public function hasClass(string $className): bool;

    public function getClass(string $className): ClassReflection;
}

Call sites change mechanically:

-use PHPStan\Reflection\ReflectionProvider;
+use Rector\Reflection\ClassReflectionProvider;

 final class FinalizeTestCaseClassRector extends AbstractRector
 {
     public function __construct(
-        private readonly ReflectionProvider $reflectionProvider,
+        private readonly ClassReflectionProvider $classReflectionProvider,
         private readonly VisibilityManipulator $visibilityManipulator
     ) {
     }
 ...
-        if (! $this->reflectionProvider->hasClass($className)) {
+        if (! $this->classReflectionProvider->hasClass($className)) {
             return null;
         }

-        $classReflection = $this->reflectionProvider->getClass($className);
+        $classReflection = $this->classReflectionProvider->getClass($className);

Some files lose their last PHPStan import outright:

 namespace Rector\Skipper\SkipVoter;

-use PHPStan\Reflection\ReflectionProvider;
+use Rector\Reflection\ClassReflectionProvider;

Why

ReflectionProvider was imported in 68 files, but only 6 of its methods were ever called — and 55 files used nothing but hasClass() / getClass(). That is a wide import surface over a very narrow API.

Routing it through one class means a future change to how Rector resolves class reflection has a single edit point instead of 68.

Numbers

	before	after
files importing ReflectionProvider	68	16
rules/ files importing any PHPStan\	342	336
changed files with zero phpstan/phpstan imports	0	10

The 16 remaining are engine internals (PHPStanNodeScopeResolver, NodeTypeResolver, AstResolver, ReflectionResolver, the DI factories) plus rules doing function/constant lookups — those need hasFunction() / getFunction() / hasConstant() / getAnonymousClassReflection(), deliberately left out of this facade. A function-lookup equivalent can follow separately.

No behaviour change: the facade delegates straight to the same ReflectionProvider instance, resolved by autowiring from the existing PUBLIC_PHPSTAN_SERVICE_TYPES registration.