Move custom function logic out of pubsub_trigger and into it's own function

[dgwhited]

Is your feature request related to a problem? Please describe.
We should move existing logic out of the pubsub_tigger logic so that it is easier to read and template out new remediations.

Describe the solution you'd like
Trigger should check if the resource is in an enabled project, and then call the remediation function that has the custom logic.

Describe alternatives you've considered
With the new allow/deny list logic, all of the custom code goes into a if else block.