refactor(instr-mongodb): use exported strings for attributes

[david-luna]

Which problem is this PR solving?

• Updates Update usage of semantic conventions to new exported strings #2025

Short description of the changes

• Update @opentelemetry/semantic-conventions to ^1.22
• Replace SemanticAttributes.* with exported strings SEMATTRS_*
• Update README with new semantic convention package version and key

[codecov]

Codecov Report

Merging #2088 (5a71fb4) into main (dfb2dff) will decrease coverage by 0.16%.
Report is 46 commits behind head on main.
The diff coverage is 100.00%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2088      +/-   ##
==========================================
- Coverage   90.97%   90.82%   -0.16%     
==========================================
  Files         146      148       +2     
  Lines        7492     7672     +180     
  Branches     1502     1537      +35     
==========================================
+ Hits         6816     6968     +152     
- Misses        676      704      +28     

Files	Coverage Δ
...try-instrumentation-mongodb/src/instrumentation.ts	47.42% <100.00%> (-5.85%)	⬇️

... and 12 files with indirect coverage changes