fix(instrumentation-http): add server attributes after they become available

[pichlermarc]

Which problem is this PR solving?

While reviewing #5079 I noticed that we don't set http.route and http.response.status code in the server duration metrics, so this PR addresses a few problems:

• We did not add http.route to the Span on "new" metrics
• We add the http.route only when DUPLICATE emission is turned on because
  • we also didn't add it to the Span for "new" metrics
  • but we did add it for the "old" metrics and the attribute name happens to match
• we never added the http.response.status code, because
• it is not yet determined when we add it (before the request is handled)

NOTE: skipping changelog because this is a bug in an unreleased feature

Supersedes #5079
Related to #5026

Type of change

• Bug fix (non-breaking change which fixes an issue)

How Has This Been Tested?

• Added assertions to unit tests

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 93.26%. Comparing base (be1737f) to head (ec50dc6).
Report is 3 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #5081      +/-   ##
==========================================
- Coverage   93.27%   93.26%   -0.02%     
==========================================
  Files         317      317              
  Lines        8195     8195              
  Branches     1641     1641              
==========================================
- Hits         7644     7643       -1     
- Misses        551      552       +1     

see 1 file with indirect coverage changes

[klippx]

Nice! When will this be released on NPM? Just asking, because I noticed that #5079 was not released yet, only merged. Not sure what the current state is.

[pichlermarc]

Nice! When will this be released on NPM? Just asking, because I noticed that #5079 was not released yet, only merged. Not sure what the current state is.

We'll release once all of these things listed in the comment here are done. 🙂