Integration test fixes for CI pipeline

[gavin-aguiar]

Description:
CI pipelines were failing with module not found error for test/utils.
Pytest installed in the agent could not find tests/utils module since its not a part of the azure-functions-worker.
When you run pytest directly, the command is executed as a script and assumes that pytest is installed and available in the system's PATH. Using python -m pytest invokes the pytest module as a package through the Python interpreter. This way all the modules within the root folder are added to sys.modules.

Fixes #1230

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PR information

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• New Unit tests were added for the changes made and CI is passing.

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[codecov]

Codecov Report

Merging #1259 (0e9ce79) into dev (78274ef) will decrease coverage by 53.26%.
The diff coverage is n/a.

❗ Current head 0e9ce79 differs from pull request most recent head 58da026. Consider uploading reports for the commit 58da026 to get more accurate results

@@             Coverage Diff             @@
##              dev    #1259       +/-   ##
===========================================
- Coverage   85.24%   31.98%   -53.26%     
===========================================
  Files          34       34               
  Lines        1904     1904               
  Branches      366      366               
===========================================
- Hits         1623      609     -1014     
- Misses        219     1294     +1075     
+ Partials       62        1       -61     

Flag	Coverage Δ
unittests	31.98% <ø> (-53.21%)	⬇️

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see 24 files with indirect coverage changes