Investigate alternative multipart parsers

[gurgunday]

Prerequisites

• I have written a descriptive issue title
• I have searched existing issues to ensure the issue has not already been raised

Issue

For instance remix parser seems to be quite faster than @fastify/busboy and is async generator based

In theory we should be able to use it, but we should test the speed claims in the context of Fastify

Related to #464

[climba03003]

From the benchmark script, it seems to buffer chunk into memory by default.
https://github.com/mjackson/multipart-parser/blob/main/bench/parsers/multipart-parser.ts#L22-L24

[gurgunday]

Yeah I did some testing and it's really hard to beat fastify/busboy in practical cases, I think it should stay for now

[gurgunday]

I'll open this again, some of the concerns like not having a size limit were addressed and their benchmark still shows significant improvements with simpler code.

Even if it's not the case, I'd like to use this issue as a temporary placeholder to investigate alternatives.