MultiPartBody: Impossible to add multiple Body Parts with the same name

[wim-kaspar]

First of: I know an issue with this exact title exists, but it is not solved in my opinion. (I added a comment but cannot reopen it)

What are you generating using Kiota, clients or plugins?

API Client/SDK

In what context or format are you using Kiota?

Nuget tool

Client library/SDK language

Csharp

Describe the bug

I am using an existing API with the Atteached API Spec.

In the previous issue the user faced the same issue with multiple files with the same name. It was then solved by adding the filename as descriminator. However, I don't have a file name to use.

I think the underlying type of form data has to change from a dictionary to a list for this to work.

Expected behavior

Be able to create a multipart body with multiple elements with the same name.

How to reproduce

Generate client with attached API spec.

Try add multiple values for multiValue

Open API description file

openapi: 3.0.3
info:
  title: Poc
  version: 0.0.1
paths:

  '/api/multipart':
    post:
      operationId: postFileAndData
      requestBody:
        content:
          multipart/form-data:
            schema:
              type: object
              properties:
                singleValue:
                  type: integer
                multiValue:
                  type: array
                  items:
                    type: string
      responses:
        201:
          description: created

Kiota Version

1.28.0+57130b1b1db3bc5c060498682f41e20c8ae089f2