chore: Removed unused attributes on LlmChatCompletionSummary and LlmEmbedding

[bizob2828]

Description

Removed attributes around legacy token counts on summary. I also fixed the embedding event to only calculate token_count if callabck is specified. Lastly, removed transaction_id from all events.

Related Issues

Closes #265

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 97.67%. Comparing base (ce0d324) to head (dc726b3).

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #278      +/-   ##
==========================================
- Coverage   98.00%   97.67%   -0.34%     
==========================================
  Files          23       23              
  Lines        2008     1980      -28     
==========================================
- Hits         1968     1934      -34     
- Misses         40       46       +6     

Flag	Coverage Δ
unit-tests-16.x	45.80% <100.00%> (-0.96%)	⬇️
unit-tests-18.x	45.80% <100.00%> (-0.96%)	⬇️
unit-tests-20.x	45.80% <100.00%> (-0.96%)	⬇️
versioned-tests-16.x	97.42% <100.00%> (-0.34%)	⬇️
versioned-tests-18.x	97.42% <100.00%> (-0.34%)	⬇️
versioned-tests-20.x	97.42% <100.00%> (-0.34%)	⬇️

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