This change is made to comply with the new Symfony standards and to avoid deprecation warnings for future versions. The update touches various functionalities, including retrieving EntityManagerInterface instance and various service classes within the test files.
Serializer groups have been added to the SignedUrl and SignedUrlPost classes to ensure correct serialization. Two new test files were also included: SignedUrlNormalizerTest and SignedUrlPostNormalizerTest which test the normalization of instances of the classes.
