This adds safe guards to the Audit notification class where somehow $item was null. Now an exception is thrown before parsing $item for a notification.

This also adds google workspaces to audit notifications, I somehow did not add this before. But it is added now:

This also adds two tests.
The first, tests the the exception throws for $item being null.

The second, tests that an Audit notification is sent. This tests delivery to Slack, Teams, and Google workspace webhooks.