Name handler for child classes

[Kaoticz]

Adds the property TypeNameHandler to BaseLanguageOptions, so library users can overwrite the type name given to custom child objects in the Json object.

// BaseLanguageOptions
public abstract Func<string, string> TypeNameHandler { get; init; }

The function takes the raw name of the JSON property and is expected to return the name of the property type in the class.
You can define your own implementation and return whatever name you want for the class. Default implementations are provided for convenience. They are language-specific and follow the naming convention for their respective languages.

Default implementation for C#:

// Json2SharpCSharpOptions : BaseLanguageOptions
public override Func<string, string> TypeNameHandler { get; init; } = static propertyName => propertyName.ToPascalCase();

Sample usage:

var options = new Json2SharpOptions()
{
    TargetLanguage = Language.CSharp,
    
    CSharpOptions = new()
    {
        TypeNameHandler = propertyType => propertyType.ToUpperInvariant() + "AYY"
    }
};

The option above would append "AYY" to the names of all child classes in upper case: blep -> BLEPAYY