fix: use user id and anonymous id as segment identity COMPASS-5487

[alenakhineika]

Description

In Compass, we don't have any MongoDB user identifiers. We randomly generate an ID the first time the product is run and then we use that as a user id. The userId telemetry field should not store the random UUID, it should store only AUID. The randomly generated UUID should be stored as anonymousId.
To not break statistics for existing users:

• We should leave all current users with the tracking they have.
• For new users, we should use the field anonymousID and fill it with a random UUID.

That being said:

• If userId exists we send it to segment. We also copy userId to anonymousId and send it to segment as well.
• If userId does not exist we do not create a new one, we only generate a random UUID and send it to segment as anonymousId.

Checklist

• New tests and/or benchmarks are included
• Documentation is changed or added

Motivation and Context

• Bugfix
• New feature
• Dependency update
• Misc

Types of changes

• Backport Needed
• Patch (non-breaking change which fixes an issue)
• Minor (non-breaking change which adds functionality)
• Major (fix or feature that would cause existing functionality to change)

[mcasimir]

👍

[mcasimir]

Hyper super NIT, no need to change anything. Should this be called just segmentAnonymousId without current? i think "current" in currentUserId is an adjective of user rather than of id: "the id of the current user". Here it almost seems like there is a currentSegmentAnonymousId cause there may be another SegmentAnonymousId that's not "current".

[mcasimir]

Another NIT, and again no need to change anything, but to your point of making this a bit more "generic" and less segment-specific, maybe another possible name could be telemetryAnonymousId. LGTM either way feel free to merge as is.