feat(deno-runtime): restart app process if it times out consecutively

[d-gubert]

What? ⛵

Extracted two new components from the DenoRuntimeSubprocessController class:

• ProcessMessenger - controls transport of messages to the subprocess
• LivenessManager - controls the ping processes and restarts

Refactor the ping functionality to add the following:

• Keep track of consecutive ping timeouts. If reaches limit (currently 4), tries to restart the subprocess
• Keep track of restarts. If reaches limit (currently 3), stops restarting and leaves app in "broken" state
• Pings will now be aborted if the process exits (either due to a Deno error or a kill)
• Pings will now only start after the process is ready.

Why? 🤔

If the Deno subprocess goes to an invalid state and stop responding, we try to restart it in hopes that this recovers the process nicely.

Links 🌎

PS 👀