Add LiteralTypeScriptExtraTypes attribute for enhanced TypeScript type definitions

[menthol]

This PR introduces a new attribute LiteralTypeScriptExtraTypes that allows adding additional literal type information to TypeScript types. This is useful when working with specifications like JSON:API where you need to add fixed properties to your TypeScript types.

Features

• New LiteralTypeScriptExtraTypes attribute that accepts an array of key-value pairs
• Each key-value pair is added as a property to the generated TypeScript type
• Values are inserted as literal TypeScript code, allowing for complex type definitions

Examples

Basic usage with a string literal:

#[TypeScript]
#[LiteralTypeScriptExtraTypes([
    'type' => "'users'",
])]
class UserData {
    public string $name;
}

Generates:

export type UserData = {
    type: 'users';
    name: string;
};

Multiple properties with complex types:

#[TypeScript]
#[LiteralTypeScriptExtraTypes([
    'type' => "'users'",
    'links' => '{self: string}',
])]
class UserData {
    public string $name;
}

Generates:

export type UserData = {
    type: 'users';
    links: {self: string};
    name: string;
};

[menthol]

During development, I have considered several alternative names for this attribute:

• LiteralExtraTypeScriptTypes
• TypeScriptExtraTypes
• AdditionalTypeScriptTypes
• TypeScriptExtra (and the overwriting of the transformExtra function)