perf(instrumentation-nestjs-core): extract reusable span attributes to outer scope

[Samuron]

Which problem is this PR solving?

Reduce overhead of nestjs instrumentation

Short description of the changes

Pulled some parts of instrumentation to enclosing scope to reuse and reduce allocations

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 95.68%. Comparing base (dfb2dff) to head (2f82d70).
Report is 89 commits behind head on main.

❗ Current head 2f82d70 differs from pull request most recent head 1b18180. Consider uploading reports for the commit 1b18180 to get more accurate results

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2087      +/-   ##
==========================================
+ Coverage   90.97%   95.68%   +4.70%     
==========================================
  Files         146       11     -135     
  Lines        7492      788    -6704     
  Branches     1502      164    -1338     
==========================================
- Hits         6816      754    -6062     
+ Misses        676       34     -642     

see 136 files with indirect coverage changes

[blumamir]

LGTM, thank you for the contribution