Symfony 7 support

• See #67
• Includes removal of InteractiveFormContainerAwareCommand

Don't override data fields if they have not been submitted as input option in non-interactive mode

See #61

Fix bug with DataTransformers and AbstractTextInputBasedTransformer

See #60

Allow non-compound forms and nested forms default values from command options

See #58

Take "choice_value" option into account for default values

See #57

Show translated help message when provided

See #56

Prevent fatal error when default value of choice type is not stringable

See #54

Fix type incompatibilities

See #52 and #53

Add support for Symfony 6

See #51

Also replacing PHP-CS-Fixer with ECS, improving the Docker setup (and describing how to use it in CONTRIBUTING.md)

v5.0.0: Merge pull request #47 from matthiasnoback/fix_default_style

See #47