node: CJS loader shouldn't require full read access.

Currently, trying to use CJS loader you get following error:

error: Uncaught Error: CJS loader requires --allow-read.
      throw new Error("CJS loader requires --allow-read.");
            ^

It’s not strictly required to have full disk read access, the loader should work perfectly fine with access to the current directory.

CC @kt3k

[bartlomieju]

Discussed this offline with @ry, jumping to adding sync permissions API is not a good idea. We should change the error message in such a way that doesn’t suggest completely opening the sandbox for read operation, so maybe something like:

CJS loader requires read permissions. If packages are installed locally try passing --allow-read=node_modules/ flag.

Alternatively we could completely skip mapping an error to a new one and just return the default error message.

[bartlomieju]

I just tried to see if this solution is feasible and there’s a hiccup. APIs that are stating file system are all synchronous, while Deno.permission.request is an async API. There’s not much room for work arounds here as the APIs are ported from Node (eg. Module._findPath). Without synchronous permissions API we might not be able to handle that.