[TYPESCRIPT-ANGULAR] Filename during upload

Description

Modelling a rest service to upload a file using swagger 2.0 result in a default implementation in typescript with "Blob" type. This class does not specify a filename, so instead a File class must be used, because File extends Blob and specify a filename

Swagger-codegen version

2.3.1 ( I think current stable is behind https://editor.swagger.io too )

Swagger declaration file content or url

swagger: "2.0"
info:
  version: "0.1"
  title: "TEST UPLOAD"  
basePath: "/rest"
schemes:
- "http"
host: localhost:8080
paths: 
  /file/xml:
    post:
      consumes:
      - "multipart/form-data"
      parameters:
      - in: formData
        name: upfile
        type: file
        required: true
      produces:
      - "application/json"
      responses:
       200:
        description: file uploaded
        schema:
          type: string

Command line used for generation

Using https://editor.swagger.io/

Steps to reproduce

1. go to https://editor.swagger.io/
2. paste provided yaml
3. generate-client -> typescript-angular
4. unzip result
5. go to /api folder
6. open default.service.ts
7. at row 65,66,67,68 generated methos are:

public fileXmlPost(upfile: Blob, observe?: 'body', reportProgress?: boolean): Observable<string>;
    public fileXmlPost(upfile: Blob, observe?: 'response', reportProgress?: boolean): Observable<HttpResponse<string>>;
    public fileXmlPost(upfile: Blob, observe?: 'events', reportProgress?: boolean): Observable<HttpEvent<string>>;
    public fileXmlPost(upfile: Blob, observe: any = 'body', reportProgress: boolean = false ): Observable<any> {

8. why upfile type is Blob instead of File ?

Related issues/PRs

No one found

Suggest a fix/enhancement

Reproduce the issue with the provided Swagger 2.0 definition using the typescript-angular generator, then inspect the generated /api/default.service.ts entry point. Trace the generator template or type mapping that produces the Blob parameter and verify the generated upload signature against the expected filename-carrying type.