Add benchmark tests

[kohrapha]

Description:
This CR adds benchmarking tests for the AWS EMF Exporter.

Testing:
The new benchmarking tests were run locally.

Documentation:
N/A

[codecov]

Codecov Report

Merging #1399 into master will decrease coverage by 0.01%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #1399      +/-   ##
==========================================
- Coverage   89.87%   89.86%   -0.02%     
==========================================
  Files         328      328              
  Lines       16081    16081              
==========================================
- Hits        14453    14451       -2     
- Misses       1184     1185       +1     
- Partials      444      445       +1     

Flag	Coverage Δ
#integration	68.89% <ø> (ø)
#unit	89.11% <ø> (-0.02%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
receiver/k8sclusterreceiver/watcher.go	95.29% <0.00%> (-2.36%)	⬇️

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[anuraaga]

Thanks!

[tigrannajaryan]

Please rebase. Failing tests should pass now.

[kohrapha]

@tigrannajaryan done!