[CAL-4586] handleNotificationWhenNoSlots false positives

[zomars]

Right now we trigger an email alert whenever we receive and empty slots object.

We need to make some improvements here:

• Add the requested start and end date to the alert so we know exactly the range that triggered the alert.
• Add webhook alert option (so it can be linked to Zapier, Slack, etc.)
• Don't trigger the alert if the range is triggered due to limit settings:
  • Limit bookings to X days in the future
  • Limit bookings per day, week, month, etc
• Optional: allow to configure alert thresholds:
  • Trigger on X instances
  • Trigger for specific event types

_{From SyncLinear.com | CAL-4586}

[zomars]

cc @CarinaWolli for prioritization and assignment

[sean-brydon]

The major issue that was causing pain here is fixed. We now only send emails to the team admins of the event rather than the entire organisation. This was fixed here: https://github.com/calcom/cal.com/pull/17430

The rest of the issues that are mentioned in this PR arent has high prio. Will drop this down to low for the time being