feat(otlp-exporter-base): add http response body to exporter error

[pichlermarc]

Which problem is this PR solving?

When exporting via OTLP we currently don't include the response body recevied from the remote in the error we return. This makes it difficult for users to see what's wrong. This PR addresses this by adding the response to the data of the OTLPExporterError

Fixes #5201

Type of change

• New feature (non-breaking change which adds functionality)

How Has This Been Tested?

• Added assertion in unit tests

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 94.59%. Comparing base (c9fa209) to head (06d4874).
Report is 3 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #5204      +/-   ##
==========================================
+ Coverage   94.58%   94.59%   +0.01%     
==========================================
  Files         314      314              
  Lines        7993     7993              
  Branches     1611     1611              
==========================================
+ Hits         7560     7561       +1     
+ Misses        433      432       -1     

Files with missing lines	Coverage Δ
...xporter-base/src/transport/http-transport-utils.ts	100.00% <100.00%> (ø)

... and 1 file with indirect coverage changes