[Browser] Report To Different Projects By ErrorUrl

Recently we had the issue that we run three different JS projects on one site without them knowing about each other.

We needed a way to report errors from file foo.js to sentry-foo project and bar.js to sentry-bar project. We came up with ScopedSentryReporter which is now open source: https://www.npmjs.com/package/@titelmedia/scoped-sentry-reporter

I did not know where to put, because I could not find an open issue for that. So I decided to put it here and maybe get some feedback to improve our error reporting solution.

We would be really happy to get feedback, ideas and see people using it.