test: add egress tests which target pod and namespace.

[csfmomo]

Reason for Change:
Add network policy tests which target pod and namespace selector specifically.

Requirements:

• [X ] uses conventional commit messages
• includes documentation
• adds unit tests
• [X ] tested upgrade from previous version

Notes:

[jackfrancis]

/azp run pr-e2e

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[codecov]

Codecov Report

Merging #2925 into master will increase coverage by 0.07%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #2925      +/-   ##
==========================================
+ Coverage   72.49%   72.57%   +0.07%     
==========================================
  Files         141      141              
  Lines       25847    25934      +87     
==========================================
+ Hits        18739    18821      +82     
+ Misses       6021     6014       -7     
- Partials     1087     1099      +12     

Impacted Files	Coverage Δ
pkg/engine/virtualmachinescalesets.go	80.58% <0.00%> (-0.85%)	⬇️
pkg/api/vlabs/validate.go	78.20% <0.00%> (-0.62%)	⬇️
pkg/engine/virtualmachines.go	80.66% <0.00%> (-0.45%)	⬇️
pkg/api/types.go	95.21% <0.00%> (-0.43%)	⬇️
pkg/api/common/const.go	0.00% <0.00%> (ø)
pkg/engine/template_generator.go	80.96% <0.00%> (+0.02%)	⬆️
pkg/api/convertertoapi.go	93.61% <0.00%> (+0.04%)	⬆️
pkg/api/converterfromapi.go	93.80% <0.00%> (+0.04%)	⬆️
pkg/engine/armvariables.go	87.28% <0.00%> (+0.36%)	⬆️
pkg/api/vlabs/types.go	74.47% <0.00%> (+0.54%)	⬆️
... and 2 more

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[jackfrancis]

/azp run pr-e2e

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[jackfrancis]

/azp run pr-e2e

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[jackfrancis]

/lgtm

[acs-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: csfmomo, jackfrancis

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• OWNERS [jackfrancis]

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