🐛 Fix #9116 Form and File parameters order should not matter

[thomasleveil]

This PR updates the fix (6185a92) from @jsg921019 so that tests pass with the latest FastAPI code (0.110.0).
It also adds a test to cover the case with multiple files, and another to ensure the order of parameters in an endpoint definition does not affect the way FastAPI handles the request.

Problem
When declaring an endpoint which accepts a File but also a Form parameter, the File parameter must be declared first or the endpoint would respond with error 422.

Context

• See discussion Regression since v0.44.1 - Error 422 if `Form` is declared before `File` #9116
• And probably also multipart List[float] 422 bugged? #4625

[thomasleveil]

Thank you for the feed back. I pushed force with your suggested changes. Let me know if anything else can be improved.

[YuriiMotov]

The solution works.
Tests cover the issue. Tests fail before changes and pass after