Improve Node ANR (blocked event loop detection)

[timfish]

Problem Statement

Currently Node ARN has a couple of issues:

• Uses node:inspector to capture stack traces
• Starts a watchdog thread for each worker thread where the SDK is started

Solution Brainstorm

I've managed to capture stack traces across worker threads via a native module:
https://github.com/timfish/sentry-node-cross-thread-stack-trace

This native module can also be used for signaling between threads so that we can use a single watchdog thread.