[HLAPI] Event logs

[cconard96]

Checklist before requesting a review

• I have read the CONTRIBUTING document.
• I have performed a self-review of my code.
• I have added tests that prove my fix is effective or that my feature works.

Description

For v2.2.0.

• Adds event log (Event class) schema and search/get routes.
• Adds webhook support.
• Changes InternalAuthMiddleware to "authenticate" when right checks are being bypassed (Session::callAsSystem) to support webhooks when a user is not currently authenticated at all. For login events, the event is logged after the user is validated but before the session is initialized.
• Webhook Preview tab is hidden for Events because of a restriction with their DB schema and ajax/getDropdownValue.

I also evaluated adding Historical logs to the new API in this PR but have skipped it for now due to performance issues and complexity getting the id_search_option property mapped to the actual related search option information like the name, as it relies on both the id_search_option and itemtype properties.

[cconard96]

I won't have enough to warrant a new API version before next week. Switching to draft.