[Custom threshold] Use alerting framework logger

[maryam-saeidi]

Summary

In this ticket, we would like to remove the custom threshold-specific logger and use the alerting framework one instead. We can do that by removing the createScopedLogger logger and using the logger from RuleExecutorOptions instead.

[elasticmachine]

Pinging @elastic/obs-ux-management-team (Team:obs-ux-management)