Handle file:/// URLs in source-map-support cache lookup

[cspotcode]

Reported here: #1007 (comment)

https://github.com/TypeStrong/ts-node/blob/master/src/index.ts#L445-L451
Does not handle file:// URLs when checking our outputCache. ESM modules have a URL instead of a path. So source-map-support is unable to get access to the sourcemaps, and stack traces are wrong for ESM modules.

Fix is to robustly check for a file URL. If found, convert to a path, then normalize slashes, then lookup in the cache.

Node's url.fileURLToPath should help.