Implement event-based instrumentation for web errors

[martinkuba]

This should be a new package with instrumentation that generates events for browser unhandled errors and errors that happen outside of spans.

The instrumentation should use only the Events API as a dependency for generating the event.

The instrumentation should use semantic conventions defined in https://github.com/scheler/semantic-conventions/blob/browser-events-v2/docs/exceptions/exceptions-logs.md.