v2.0.0: Rewrite with PHP 8.1 enums

This is a complete rewrite of the library to leverage & add new capabilities over new PHP 8.1 native enums.
Some features are still awaited (#124), but the main interfaces should not change by now, and the library will be improved in the next minor releases.

Thanks to every contributor who helped moving forward to this new version 🎉 ✨

Changelog

[e841eb6] feature #165 V2: Rewrite with PHP 8.1 enums (@ogizanagi)
[0bc5a0b] feature #167 Add VarDumper caster for readables (@ogizanagi)
[e4dacde] feature #168 Add VarDumper caster for flag bag (@ogizanagi)
[2aefece] feature #169 [HttpKernel] Add a controller argument resolver for backed enums (@ogizanagi)
[55781e1] minor #171 [Docs] Mention the official Doctrine ORM integration (@ogizanagi)
[7d08ee2] minor #173 fix phpstan phpdoc (@Kleinast)
[ec16823] bug #174 Override the block prefix (@benji07)
[c447d57] minor #175 Throw bad method call on attempt to call ReadableEnumTrait::readableForValue on non backed enum (@ogizanagi)
[1a1c3d6] feature #170 Allow to provide extra values to EnumCase attribute (@ogizanagi)
[27e0c46] feature #177 add Faker provider (@IonBazan, @ogizanagi)
[ad2d4fd] feature #176 Add Doctrine ODM integration (@IonBazan)
[98a03f3] feature #181 Add FlagBag::fromAll to instantiate a bag with all of its flags (@michnovka)
[7600213] feature #183 FlagBagType support (@michnovka)
[e623ba2] feature #182 Add SQL Enum support (@michnovka, @ogizanagi)
[7a6c730] feature #186 Initial DBAL FlagBag support (@michnovka)
[e6735d6] minor #187 Add missing ODM extensions test + XSD types (@ogizanagi)