Better handling around specific exit codes of language worker (codes 0 and 200)

A worker can exit with process code 0 or 200 due to user code (ex: `process.exit()` for Node.js), and this will mean that all subsequent executions will be accepted and inevitably time out.

We should be doing something on our end to either make sure that this cannot happen (currently, we do nothing [if a process exits with code 0](https://github.com/Azure/azure-functions-host/blob/dev/src/WebJobs.Script/Workers/ProcessManagement/WorkerProcess.cs#L139)).

cc: @pragnagopa and @yojagad