Fix for OneOf Subtyping - Generators were failing to generate proper discriminators

[pixellos]

Tested on generators:

• TypeScript
• TypeScript-fetch

Given:

• User is using subTypes to create polymorphic ode

Whe:

• Code is generated

Then

• Discriminators are not taken into account

Should:

• Code should be discriminators aware

Old behavior:
Generated code with discriminators not compiling

No discriminators:

export class Base {
    'str': string;
    'i': number;

    static readonly discriminator: string | undefined = undefined;

    static readonly attributeTypeMap: Array<{name: string, baseName: string, type: string, format: string}> = [
        {
            "name": "str",
            "baseName": "str",
            "type": "string",
            "format": ""
        },
        {
            "name": "i",
            "baseName": "i",
            "type": "number",
            "format": "int32"
        }    ];

    static getAttributeTypeMap() {
        return Base.attributeTypeMap;
    }
    
    public constructor() {
    }
}

export class A {
    'str': string;

    static readonly discriminator: string | undefined = undefined;

    static readonly attributeTypeMap: Array<{name: string, baseName: string, type: string, format: string}> = [
        {
            "name": "str",
            "baseName": "str",
            "type": "string",
            "format": ""
        }    ];

    static getAttributeTypeMap() {
        return A.attributeTypeMap;
    }
    
    public constructor() {
    }
}

Expected Behavior (current):

export class Base {
    'type'?: string;
    'i': number;
    'l': number;

    static readonly discriminator: string | undefined = "type";

    static readonly attributeTypeMap: Array<{name: string, baseName: string, type: string, format: string}> = [
        {
            "name": "type",
            "baseName": "type",
            "type": "string",
            "format": "string"
        },
        {
            "name": "i",
            "baseName": "i",
            "type": "number",
            "format": "int32"
        },
        {
            "name": "l",
            "baseName": "l",
            "type": "number",
            "format": "int64"
        }    ];

    static getAttributeTypeMap() {
        return Base.attributeTypeMap;
    }
    
    public constructor() {
        this.type = "Base";
    }
}


export class B {
    'i': number;
    'type'?: string;

    static readonly discriminator: string | undefined = "type";

    static readonly attributeTypeMap: Array<{name: string, baseName: string, type: string, format: string}> = [
        {
            "name": "i",
            "baseName": "i",
            "type": "number",
            "format": "int32"
        },
        {
            "name": "type",
            "baseName": "type",
            "type": "string",
            "format": "string"
        }    ];

    static getAttributeTypeMap() {
        return B.attributeTypeMap;
    }
    
    public constructor() {
        this.type = "B";
    }
}

[pixellos]

@Wicpar
Can U throw an eye?

[Wicpar]

Looks good to me, not too happy about the formatting changes though as it makes it harder to see the actual changes, but that's ok.