Improve nginx/anonymous endpoint performance

[elpablos]

Why?
If the endpoint /cookie/nginx/anonymous is under heavy load, MongoDB is suffering because of a big bunch of write operations into audit collection. Especially for one event: ANONYMOUS_SESSION_CREATED. We found out that this information is not so important to us and it is not necessary to put it into the audit.

Another place that generates big traffic is the synchronous cookie webhook. We found out that the important information is only when the anonymous user fulfills the login process and becomes a fully logged user. So it makes sense to avoid calls when an anonymous session is just built.

DoD

• make a config switch for ANONYMOUS_SESSION_CREATED audit event (Disable auditing anonymous sessions #304)
• make a config switch for cookie webhook when anonymous session is created (Regulate cookie webhook for anonymous sessions #308)

EDIT:

• I have found out this issue Consider unification of ANONYMOUS_SESSION_CREATED and LOGIN_SUCCESS in audit log #225 and it needs to be solved together!

[elpablos]

#304 - It's just a draft but it really helps 😅
Do with the PR whatever you want. I thought about config variables 🤔