Audit logs cannot be restored because of id conlicts

Follow up of https://github.com/authgear/authgear-server/pull/3499#issuecomment-1827141271

https://github.com/authgear/authgear-server/blob/705f4641a46d4fcf7e523ad6e956e5a30337a718/pkg/lib/event/store.go#L14

The ids are generated using a sequence in the database, which can cause conflict in different databases.

Start with pkg/lib/event/store.go around line 14 and read the follow-up discussion in pull request 3499. Trace how audit-log IDs are generated and how restoration moves data between databases. Done means audit logs can be restored across databases without ID conflicts.

Written by the indexing model from the issue text.