Enabling a larger max_part_size for multipart forms

[taiyosogawa]

I'm trying to figure out how to increase the max_part_size for multipart forms, which appears to be fixed to 1MB since this commit.

@Kludex, thanks for putting that security feature in - I'm wondering if there's a good way to configure it as-is or what your thoughts would be to add a way to configure it for specific scenarios?

My use case is to integrate with Twilio SendGrid's inbound parse webhooks. Whenever an email is received, SendGrid will POST the contents and all the attachments of that email to my FastAPI server. The attachments are expected to exceed 1MB and they are sent as a multi-part form (docs with example payload). I don't have any control over how they push that data, otherwise I might find an alternative method.

Thank you in advance for your thoughts and suggestions!