Change TOML parser to an active project that supports the latest TOML syntax

[jacob-8]

Describe the bug
I upgraded to the most recent wrangler version and expected adding upload.format = "service-worker" to the wrangler.toml (for adapter-cloudflare-workers) file to just work as described in https://developers.cloudflare.com/workers/cli-wrangler/configuration#service-workers but when the adapter (https://github.com/sveltejs/kit/blob/master/packages/adapter-cloudflare-workers/index.js#L61) parses it with the toml package it throws:
Error parsing wrangler.toml: Expected "=", [ \t] or [A-Za-z0-9_\-] but "." found.

To Reproduce

• npm init svelte@next and npm i
• npm i -D @sveltejs/adapter-cloudflare-workers@next and add import cloudflare from '@sveltejs/adapter-cloudflare-workers'; and adapter: cloudflare(), to svelte.config.js
• wrangler init (assumes you've installed wrangler globally)
• To the newly created wrangler.toml file add

[build]
upload.format = "service-worker"

or any other wrangler instruction using the . syntax.

• npm run build <-- Bug throws here

Expected behavior
I expected the build to complete successfully and for me to be able to then publish the built site using wrangler publish.

Information about your SvelteKit Installation:

- @sveltejs/adapter-cloudflare-workers": "^1.0.0-next.8" - @sveltejs/kit: "next"

Severity
Annoying but not a show-stopper presently because I can use an alternate syntax:

[build.upload]
format = "service-worker"

Additional context
The problem is caused by using the stale toml package which hasn't been updated in 2 years and is still back at the 0.4.0 TOML spec. I propose opening a PR to switch to using https://www.npmjs.com/package/@iarna/toml or some other Javascript package (see https://github.com/toml-lang/toml/wiki) which is up to date with the latest TOML spec as done by others to parse the wrangler.toml properly when using TOML syntax introduced after 0.4.0. Can I open a PR?

Someone proposed support for TOML 0.5.0 to the stale toml package, but no dice as the package maintainer is no longer responding: BinaryMuse/toml-node#50

[benmccann]

Sounds reasonable to me. @halfnelson wrote the adapter originally so tagging him here in case he wants to weigh in

https://github.com/sveltejs/kit/pull/717/files#diff-43081842b4f8656d01e0b6705906f558acf5f309ea11076f4de04a01d5ecb39fR14

[halfnelson]

Good idea!

[halfnelson]

We should also bump/change the package used in the Netlify adapter too