Milestone M28 updates

Let's go through what we got done in Milestone M28 (Jan 13 - Jan 26).

• For some sessions, the fullsnapshot event was missing, which caused the session recording to become corrupted. A fix has been added on the widget side to capture the fullsnapshot using the rrweb function if it is not captured automatically in the first batch of events.

• To ensure secure communication between the Lambda function and the Replay server, an authentication token has been introduced in the Lambda function.