I noticed that:

- The web and electron versions of our `uuid` module both looked exactly
the same…
- …and deferred to the `uuid` package…
- …and the async version just called the sync API.

So now we will just use the `uuid` package directly everywhere.

Closes #944, closes #532. ~WIP because something is causing the test
budget to fail to create because it’s using INSERT instead of UPDATE sql
queries. (Or not? I have no idea)~

This PR converts everything (aside from electron) from CommonJS to ESM.
It is needed to reduce the changes that will happen during the migration
to Typescript (as TS does not play nice with CJS).

Basically:
- rewrite `require()` to `import`
- rewrite `module.exports` to `exports`
- introduce `ts-node` to run importers so we can convert them to TS too

Lastly, sorry for this larg-ish PR, not my preference but when I tried
to reduce its scope, I would end up with mixed commons/esm that was even
more tricky to handle.

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Closes #399