[CodeQuality] Add AddIntersectionParamToMockObjectParamRector

[TomasVotruba]

Private test methods that take a mock end up with a bare MockObject param type — either handwritten, or produced by ExpectsParamToMockObjectRector. The mocked class is then lost for static analysis, which is what forces @phpstan-ignore-next-line on every call on that param.

This rule puts the class back into an intersection @param, resolved from the mock actually passed at the call sites in the same class.

 final class SomeTest extends TestCase
 {
     public function testBuildForm(): void
     {
         $builder = $this->createMock(FormBuilderInterface::class);
         $eventListener = $this->getEventListenerFromBuildForm($type, $builder);
     }

+    /**
+     * @param \FormBuilderInterface&\PHPUnit\Framework\MockObject\MockObject $builder
+     */
     private function getEventListenerFromBuildForm(SomeType $type, MockObject $builder): callable
     {
         $builder->expects($this->once())
             ->method('addEventListener');
     }
 }

How the type is resolved

Only private methods are handled, as those can only be called from the very same class, so all call sites are visible.

The mocked class comes from the $this->createMock(Some::class) / self::createMock(Some::class) assignment of the passed variable, or from a createMock() call passed inline as an arg.

Skipped when the type would be a guess:

• call sites disagree on the mocked class
• no call site at all
• the variable is re-assigned, so its type is not certain
• createStub() source, that is a Stub, not a MockObject
• a @param tag for that param already exists, to not contradict it
• non-test class, public/protected method, variadic param

Sets

Registered in the composer-based set next to ExpectsParamToMockObjectRector, bonded to phpunit/phpunit >=11.0 to match its stub/mock siblings, and in the phpunit-mock-to-stub set.

Note on the intersection order: this prints \Some&\MockObject, while the existing AddIntersectionVarToMockObjectPropertyRector prints \MockObject&\Some. Happy to flip either one for consistency.