Summary

This PR adds type declarations to the scalar type class stub generated by the make:graphql:scalar command.

The ScalarType class uses the NamedTypeImplementation trait, which declares the following typed properties:

public string $name;
public ?string $description;

https://github.com/webonyx/graphql-php/blob/master/src/Type/Definition/NamedTypeImplementation.php#L10-L12

However, the current scalar.stub generates classes without type declarations, causing the following Fatal errors:

Fatal error: Type of SomeScalarType::$name must be string 
Fatal error: Type of SomeScalarType::$description must be ?string 

Added type declarations to the stub file src/Console/stubs/scalar.stub so that generated scalar type classes satisfy the parent class's type requirements:

+ public string $name = 'DummyClass';
- public $name = 'DummyClass';

+ public ?string $description = '';
- public $description = '';

Type of change:

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update
• Misc. change (internal, infrastructure, maintenance, etc.)

Checklist:

• Existing tests have been adapted and/or new tests have been added
• Add a CHANGELOG.md entry
• Update the README.md
• Code style has been fixed via composer fix-style