feat: Add support for device code grant

[SimonVanacco]

This PR adds support for device code grants, which has been available for some time in oauth2-server

Ready to be tested, I'd love to get some feedback if you think some areas could be improved !

Design considerations

• I've decided to let end-users handle the device code verification page on their own. This is to prevent having to require twig in the bundle itself and create more complexity to accommodate all use cases. An example controller has been added in the documentation
• This does not support verification_uri_complete, only verification_uri
• Logic for code approval is in DeviceCodeRepository::approveDeviceCode. I was unable to re-use the logic from oauth2-server as they fetch the code by "device_code" instead of by "user_code". Not sure if this is a mistake in the parent bundle or some use-case I don't understand, but it does not accommodate most people use-cases. I'm open to moving the logic somewhere else if you find a better place for it !
• I've added some basic tests but this is not my strong suit : please let me know if I missed something :)

[chalasr]

Thanks for the PR! Can you rebase it? Here are some comments also

[chalasr]

Suggested change

	# Password grant handling
	# Device grant handling

[chalasr]

Suggested change

[chalasr]

Suggested change

[chalasr]

Suggested change

	return $this->entityManager->createQueryBuilder()
	->select('dc')
	->from(DeviceCode::class, 'dc')
	->where('dc.userCode = :code')
	->setParameter('code', $code)
	->getQuery()
	->getOneOrNullResult();
	}
	return $this->entityManager->createQueryBuilder()
	->select('dc')
	->from(DeviceCode::class, 'dc')
	->where('dc.userCode = :code')
	->setParameter('code', $code)
	->getQuery()
	->getOneOrNullResult();
	}