fix(@opentelemetry/instrumentation-user-interaction): add event listeners for each event on init

[pkanal]

Which problem is this PR solving?

• Adds event listeners on instrumentation init so that they don't have to be added manually in app code. See full explanation in this issue: [@opentelemetry/instrumentation-user-interaction] No spans created without Zone.js #1750

Short description of the changes

• Loop over event names and add event listeners for each in the init function.
• Call the init function in the constructor

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 91.03%. Comparing base (f65f2f1) to head (9fb5078).
Report is 188 commits behind head on main.

❗ Current head 9fb5078 differs from pull request most recent head 7fed08b

Please upload reports for the commit 7fed08b to get more accurate results.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1749      +/-   ##
==========================================
- Coverage   91.51%   91.03%   -0.49%     
==========================================
  Files         145      134      -11     
  Lines        7427     6683     -744     
  Branches     1486     1333     -153     
==========================================
- Hits         6797     6084     -713     
+ Misses        630      599      -31     

see 18 files with indirect coverage changes

[martinkuba]

The behavior is intended to generate spans only for events that have handlers in the application code. The handlers in application code will generally invoke other work (e.g. HTTP requests), which then make the interactions more significant (longer duration, part of a bigger trace, applicable to application logic) than just tracking all events that happen on the page. If there is a use case to track all events, I would suggest we add a new instrumentation that does not rely on Zone.js.

[JamieDanielson]

My understanding of this based on the description and Martin's comment above is this:

• The instrumentation is expected to instrument handlers added in app code
• This PR aims to add more listeners to be instrumented, without needing to add listeners to your app code

In that case I think it may be a feature instead of a bug fix, but I'm not super familiar with this instrumentation. Either way it seems this has been stalled for a bit. Is this update still something you're interested in moving forward @pkanal or is there another approach that is working for what you need?