Automatically add enctype="multipart/form-data" when there is a file input

### Is there an existing issue for this?

- [X] I have searched the existing issues

### Is your feature request related to a problem? Please describe the problem.

it is usually hard to debug null values of IFormFile when you haven't set enctype (you have no idea what's wrong)

### Describe the solution you'd like

automatically set enctype to multipart/form-data when there is a file input

### Additional context

_No response_