feat: backchannel request logging

[aarmam]

This pull request adds minor logging improvements.

• Successful back-channel logout request logging. This is useful for #2844 when trigger_backchannel_logout=true. Additionally log token for both success/failed responses.
• ID token logging in POST /oauth2/token endpoint

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 green light (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.

[codecov]

Codecov Report

Merging #3067 (e799a62) into master (a3c4304) will increase coverage by 0.06%.
The diff coverage is 57.14%.

❗ Current head e799a62 differs from pull request most recent head 381638e. Consider uploading reports for the commit 381638e to get more accurate results

@@            Coverage Diff             @@
##           master    #3067      +/-   ##
==========================================
+ Coverage   79.57%   79.63%   +0.06%     
==========================================
  Files         112      112              
  Lines        7957     7956       -1     
==========================================
+ Hits         6332     6336       +4     
+ Misses       1223     1217       -6     
- Partials      402      403       +1     

Impacted Files	Coverage Δ
consent/strategy_default.go	70.52% <57.14%> (+0.82%)	⬆️

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[aeneasr]

Awesome, thank you for your contribution! This looks pretty good and I have some ideas how to improve it further :)