log: Add EventName

[pellared]

Fixes #6182
Towards #6184

Towards #6181

Prior-art: #6018

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 82.2%. Comparing base (e108415) to head (2b00918).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##            main   #6187     +/-   ##
=======================================
- Coverage   82.2%   82.2%   -0.1%     
=======================================
  Files        273     273             
  Lines      23720   23729      +9     
=======================================
+ Hits       19521   19526      +5     
- Misses      3852    3855      +3     
- Partials     347     348      +1     

see 4 files with indirect coverage changes

[dmathieu]

Should it be added to the SDK as well? (or is that for a later PR?)

[pellared]

Should it be added to the SDK as well? (or is that for a later PR?)

Separate issue (and PR): #6183

You can find the breakdown here: #6181

I do not want to make this PR too big. I even hesitated to add enhancements to logtest but found out that this is PR should be still easy to review.