[BUG][SWIFT] Cannot upload file

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?

Description

I'm using the latest OpenAPI Generator Version to generate swift5 for our project. I was really happy to see, there is an option to also file upload. So I tried the petstore.yml version 3.

to play around with that.
The generated Swift code accept a URL instead Data for the file as type.
How can I deal with that or isn't it fully supported at the moment?
Actually I'm building the request by myself.

openapi-generator version

Latest master.

OpenAPI declaration file content or url

My config.json

{
    "projectName": "MyAPIClient",
    "responseAs": "AsyncAwait",
    "library": "urlsession",
    "removeMigrationProjectNameClass": true
}

Start by generating the Swift5 client with the provided petstore.yml uploadFile operation and the urlsession library using config.json. Inspect how the generated Swift request represents the application/octet-stream file parameter. Done means file uploads accept the expected input and the generated client sends the request successfully, with coverage for this operation.