[BUG] Models are incomplete when using typescript-axios withSeparateModelsAndApi

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator (example)?
• Have you tested with the latest master to confirm the issue still exists?
• Have you searched for related issues/PRs?
• What's the actual output vs expected output?
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Description

The models generated using typescript-axios with withSeparateModelsAndApi=true are incomplete.
Instead of using interfaces it's using only the base type and not considering the child properties.
The models are fully generated when using withSeparateModelsAndApi=false.

openapi-generator version

7.0.1

OpenAPI declaration file content or url

openapi.json

With withSeparateModelsAndApi:true

export type EmailAddressDTO = ContactDetailDTO;

With withSeparateModelsAndApi:false

export interface EmailAddressDTO extends ContactDetailDTO {
    /**
     * 
     * @type {string}
     * @memberof EmailAddressDTO
     */
    'emailAddress': string;
}

Generation Details

N/A

Steps to reproduce

I'm using the default command
npx openapi-generator-cli generate -g typescript-axios -i {input} -o {outpot} -c {config with withSeparateModelsAndApi}

Related issues/PRs

Could not find any

Suggest a fix

Check the generation of the Models in the withSeparateModelsAndApi:false and adapt it to when it's set to true

Start with the typescript-axios generator invoked by the provided openapi-generator-cli command and the attached openapi.json. Compare generation with withSeparateModelsAndApi set to true and false, then trace how model inheritance and child properties are rendered; done means the separate-model output includes the child interface properties like the emailAddress field.