Add automatic cron monitoring for cloudflare workers

[AbhiPrasad]

Description

Automatically instrument https://developers.cloudflare.com/workers/runtime-apis/handlers/scheduled/ and create cron monitors for them

[AbhiPrasad]

Because of the difficulty of automatically grabbing the cron expression from cloudflare, users have to always manually instrument their cron jobs. At the current moment this is looking like a won't do without further APIs in cloudflare workers itself.