IBX-8190: Add Symfony's Serializer support

[barw4]

🎫 Issue	IBX-8190

Related PRs:

https://github.com/ibexa/scheduler/pull/111

Description:

AdapterNormalizer

A new normalizer with low priority is implemented called AdapterNormalizer that handles data normalization or visiting data using the existing visitors. Currently, the visitors are prioritized over incoming (new) normalizers.

Unfortunately, the problem is that in order to visit value objects the Visitor and Generator have to be created and passed as arguments to ValueObjectVisitor instance.

        $valueObjectVisitor->visit($visitor, $generator, $object);

Ibexa\Contracts\Rest\Output\ValueObjectVisitorDispatcher

It is deleted now and the responsibility for finding a proper visitor is moved to the newly introduced ValueObjectVisitorResolverInterface.

Ibexa\Contracts\Rest\OutputVisitor

The visitValueObject method has to behave exactly the same as before as it's used throughout the app so we should keep BC here. I don't think we can change it to use normalizer as it uses the original Visitor's generator.

Concept made by Paweł.

For QA:

TBD

Documentation:

TBD

[Steveb-p]

Since I consulted this approach I'll give some explanations too.

Whole concept relies on using Serializer as primary entry point for data normalization.

While analyzing how Visitors worked with Generator, it became apparent that Generator basically serves as a Data Container that changes it's internal "pointer" as instructed by Visitor. This is "shared" between XML and JSON Generators, with the difference being that XML outputs it's state during this process.

So, since the primary difference between Symfony normalization and our Visitor's processing is that Symfony returns data and Visitors pass around Generator (as data storage), we can give Visitors a "fake" Generator - which whole purpose is to store data - and use it's state at the end as normalization result. This results in both processes behaving in a similar way.

[Steveb-p]

@alongosz we might want to standardize naming for encoder key, when it should be skipped in the next normalization pass, just like in your PR.

[sonarcloud]

Quality Gate passed

Issues
5 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud

[Steveb-p]

If you make getParent() part of the interface, you can declare that trying to getParent() without one would give this exception.