Add ExpectsParamToMockObjectRector for private test method params

[TomasVotruba]

Adds ExpectsParamToMockObjectRector (PHPUnit 11+), that changes the param type of a private test-case method to MockObject, when expects() is called on that param.

Since PHPUnit 10, expects() only exists on MockObject, not on the plain class type. Passing a mock into a helper method typed with the original class forces @phpstan-ignore-next-line on every expects() call:

 use PHPUnit\Framework\TestCase;

 final class SomeTest extends TestCase
 {
-    private function prepareUserMock(SomeUser $user): void
+    private function prepareUserMock(\PHPUnit\Framework\MockObject\MockObject $user): void
     {
-        // @phpstan-ignore-next-line
         $user->expects($this->once())
             ->method('getId')
             ->willReturn(1);
     }
 }

(the rule only changes the type; leftover ignore comments are removed by other tooling)

Only params with an actual expects() call are changed:

-    private function prepareUserMock(SomeUser $user, SomeUser $anotherUser): void
+    private function prepareUserMock(\PHPUnit\Framework\MockObject\MockObject $user, SomeUser $anotherUser): void
     {
         $anotherUser->getId();

         $user->expects($this->once())
             ->method('getId');
     }

Skipped:

• non-private methods, as those can be called from outside the test case
• params already typed MockObject, incl. intersection types like SomeUser&MockObject
• params with a @param docblock tag, to avoid a native type contradicting the docblock
• classes that are not test cases

Registered in the composer-based set, bound to phpunit/phpunit >=11.0, next to the related MockObjectArgCreateStubToCreateMockRector.