[Security Solutions] Fixes the newer notification system throttle res…

…ets and enabling immediate execution on first detection of a signal (elastic#114214)

## Summary

Fixes:
* Resets happening by adding the throttle to the else switches and error catching. We have to call throttle on every rule execution or we will cause a reset.
* Fixes a case where we were not firing the signal immediately by pushing down the alerts detected. This can cause a reset or a delay of MTTD. 
* Adds unit tests for the conditions
* Changes some of the logic to clean things up.

### Checklist

- [x] [Unit or functional tests](https://www.elastic.co/guide/en/kibana/master/development-tests.html) were updated or added to match the most common scenarios