feat: add event tracing

[hperl]

This implements the following events from https://github.com/ory-corp/cloud/issues/4028:

OAuth2 & OIDC

• OIDC initiated login succeeded
• OIDC initiated login failed
• Consent granted & revoked
• Consent grant aborted

Machine activity: Tokens, Permission checks
OAuth2

• Access tokens created
• Access token not created
• Access token inspected
• Access token check with result

Related issue(s)

Checklist

• I have read the contributing guidelines.
• I have referenced an issue containing the design document if my change
  introduces a new feature.
• I am following the
  contributing code guidelines.
• I have read the security policy.
• I confirm that this pull request does not address a security
  vulnerability. If this pull request addresses a security vulnerability, I
  confirm that I got the approval (please contact
  security@ory.sh) from the maintainers to push
  the changes.
• I have added tests that prove my fix is effective or that my feature
  works.
• I have added or changed the documentation.

Further Comments

[kmherrmann]

Content-wise looks great, although i can't vouch for all code changes :)

[codecov]

Codecov Report

Merging #3546 (6fabd49) into master (b183040) will decrease coverage by 0.02%.
The diff coverage is 74.50%.

❗ Current head 6fabd49 differs from pull request most recent head b960002. Consider uploading reports for the commit b960002 to get more accurate results

@@            Coverage Diff             @@
##           master    #3546      +/-   ##
==========================================
- Coverage   76.63%   76.62%   -0.02%     
==========================================
  Files         128      129       +1     
  Lines        9515     9630     +115     
==========================================
+ Hits         7292     7379      +87     
- Misses       1730     1749      +19     
- Partials      493      502       +9     

Impacted Files	Coverage Δ
driver/registry.go	23.52% <ø> (ø)
driver/factory.go	53.70% <14.28%> (-5.48%)	⬇️
driver/registry_base.go	83.69% <16.66%> (-1.55%)	⬇️
oauth2/handler.go	67.13% <83.33%> (+0.39%)	⬆️
consent/handler.go	64.16% <100.00%> (+0.60%)	⬆️
persistence/sql/persister_oauth2.go	84.28% <100.00%> (-2.13%)	⬇️
x/events/events.go	100.00% <100.00%> (ø)

[alnr]

This feels weird. Do we really need this?

[hperl]

It was in the list of needed events, so I guess? @kmherrmann ?

[aeneasr]

Maybe make it more generic and call it OAuh2FlowError ?

[hperl]

Sounds good, fixed!

[alnr]

We probably don't need this event at all. What it's trying to signal is some error during the OAuth2 flow. But many many things can go wrong during the flow, and we're not about to signal all of them to our analytics platform, are we?

Errors typically don't get emitted as analytics events but go to the monitoring platform (Grafana) as logs or error traces.

[aeneasr]

Good points Arne! I think we can still ship this for now and invest some time in better observability next. We don't have to use the events and if they serve no purpose in Analytics, we'll remove them. I agree though that this is a different concern from analytics!

[aeneasr]

Very nice, the naming of tokennotcreated is weird though

[aeneasr]

Panic: https://github.com/ory/hydra/actions/runs/5308371608/jobs/9607810461#step:6:223

[hperl]

Panic: https://github.com/ory/hydra/actions/runs/5308371608/jobs/9607810461#step:6:223

fixed :)