feat: add unit suffix support for BODY_SIZE_LIMIT

[cooolbros]

This PR adds unit suffixes support to the adapter-node BODY_SIZE_LIMIT environment variable.

Currently, achieving large byte values is only achievable with the exact byte value, and using exponents (like 1e6 to be parsed by Number) results in a byte value in base 10.

Nginx and Cloudflare both use base 2 for byte calculations (1024 based):
Nginx (source code): https://hg.nginx.org/nginx/file/default/src/core/ngx_parse.c
Cloudflare (forum question): https://community.cloudflare.com/t/is-max-upload-size-mb-1024-or-1000/239102

Adding unit suffixes to the byte values will make it easier to write and comprehend large byte values, as they can be written such as 100M instead of 104857600

Nginx also supports the size units K and M (https://nginx.org/en/docs/syntax.html) so it would be relevant for Sveltekit to support these units as well

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🦋 Changeset detected

Latest commit: f0f628b

The changes in this PR will be included in the next version bump.

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Name	Type
@sveltejs/adapter-node	Minor

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[hyunbinseo]

I am not sure why, but the updated docs is shown in the IDLE_TIMEOUT section.

[benmccann]

thanks. I fixed the bad merge