Adding Baggage api benchmark tests

[lalitb]

Fixes #837

Changes

Add performance benchmark tests for Baggage. This would be important to evaluate the performance of the internal key-value data structure used for Baggage and TraceState.
Tests are using

• 10 key-value pair entries in baggage ( Optimal scenario used most of the time).
• 180 key-value pair entries in baggage ( Max possible entries).
  with decently sized keys and values.

The result from running locally:

CPU Caches:
  L1 Data 32K (x4)
  L1 Instruction 32K (x4)
  L2 Unified 256K (x4)
  L3 Unified 8192K (x1)
Load Average: 0.38, 0.44, 0.35
----------------------------------------------------------------------------
Benchmark                                  Time             CPU   Iterations
----------------------------------------------------------------------------
BM_CreateBaggageFromTenEntries         14671 ns        14671 ns        44127
BM_ExtractBaggageHavingTenEntries        361 ns          361 ns      1853059
BM_CreateBaggageFrom180Entries        271756 ns       271757 ns         2541
BM_ExtractBaggageWith180Entries         5815 ns         5815 ns       115602
BM_SetValueBaggageWithTenEntries        2344 ns         2344 ns       301103
BM_SetValueBaggageWith180Entries       42179 ns        42179 ns        16987
BM_BaggageToHeaderTenEntries            3992 ns         3992 ns       178561
BM_BaggageToHeader180Entries           69452 ns        69451 ns         9263

For significant contributions please make sure you have completed the following items:

• CHANGELOG.md updated for non-trivial changes
• Unit tests have been added
• Changes in public API reviewed

[codecov]

Codecov Report

Merging #861 (4e24e5e) into main (a779c3b) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main     #861   +/-   ##
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  Coverage   95.50%   95.50%           
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  Files         156      156           
  Lines        6620     6620           
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  Hits         6322     6322           
  Misses        298      298