Added a feature to support additional class properties in TypeGen

[stealthAngel]

This feature allows users to define extra properties for TypeScript classes that are not present in the original C# class. Here is a sample usage in a test scenario:

private class ClassWithAdditionalPropertiesGenerationSpec : GenerationSpec
{
    public ClassWithAdditionalPropertiesGenerationSpec()
    {
        AddClass<ClassWithAdditionalClassProperties>()
            .WithAdditionalProperty("public email", "string")
            .WithAdditionalProperty("greetingMessage", "string", "'Hello, World!'")
            .WithAdditionalProperty("emptyString", "string", "''")
            .WithAdditionalProperty("creationDate", "Date")
            .WithAdditionalProperty("username", "string")
            .WithAdditionalProperty("age", "number")
            .WithAdditionalProperty("status", "'active' | 'inactive' | 'pending'");
    }
}

outputs:

export class ClassWithAdditionalClassProperties {
    // Additional properties
    public email: string;
    greetingMessage: string = 'Hello, World!';
    emptyString: string = '';
    creationDate: Date;
    username: string;
    age: number;
    status: 'active' | 'inactive' | 'pending';
}

The reason i wanted this in the first place is that i want to be able to have a type propeperty so i know what the name of my class is without changing my c# files e.g.

class Person {
public readonly type 'Person';
}

[stealthAngel]

@jburzynski can you look at this commit please

[stealthAngel]

@jburzynski Hey can I kindly ask you again to look at this, i'd really appreciate it. I want to use this feature in my project.