feat(eventtracker): Initial implementation of basic eventtracker

[javirln]

Initial implementation of an Event Tracker interface that is able to send events to a third party backend.

It creates one interface Client that is the one being called from the implementation whenever we want to track something.

Refs: #780

[migmartri]

Added image of what we discussed offline for reference

Basically

• create a generic posthog client package
• Have a telemetry package with a struct called trackCommand or similar. This telemetry package is the one that will do all the heavy lifting re: labels, env discovery and so on, the posthog package should just map TAgs into their own format and emit the event.
• we do not need a noop tracker, we can just check if the client is nil

[migmartri]

Some more additional feedback, looking good

[migmartri]

LGTM!

I left some comments on the tests, I have the feeling that we have probably used mocking too much and for use-cases where we could unit test the different parts instead.

For example, we could test the label generation/discovery by themselves, and then about calling Track just test with or without tags.

But anyways, this is more about personal preference, nothing against this code, just double check that the use of _ is idiomatic, I do not think so.

re: tests failing, I think it's detecting GitHub, you can unset it as I did here

chainloop/internal/attestation/crafter/runners/githubaction_test.go

Line 78 in 10f88c5

os.Unsetenv("CI")

Thanks!

[migmartri]

LGTM! 🚀