What kind of change does this PR introduce?

Enhancement

Description

The purpose of this is to allow bootstrapping to be more granular, by allowing extra context to be passed in from js land.

We've observed instances of using the Deno.readFileSync API in prod, but because bootstrap.js is hardcoded to block these APIs, it was difficult to react quickly to unblock them.

await EdgeRuntime.userWorkers.create({
    ..
    context: {
        useReadSyncFileAPI: true
    }
});