Add schedule:daemon command

[kbond]

• arguments:
  • --limit=x exit after running x tasks
  • --memory-limit=x exit after x memory reached
  • --time-limit=x exit after x tasks are run
• add schedule:stop-daemon or schedule:daemon --stop to stop currently running daemon (for deployment)
• document Symfony cloud config
• document production deployment similar to https://symfony.com/doc/current/messenger.html#deploying-to-production

[kbond]

One potential roadblock here is related to #6. The daemon could run out of memory or run longer than 1 minute, preventing the next minute's schedule from running.

Could the daemon just execute the schedule:run command in another process every minute? What if the process takes longer than 1 minute? It would have to be run in the background? Is this possible?