add emission of TaskEvents for Test phase

[MarlonGamez]

Related: #5422

Description
Adds emission of TaskEvents for the Test phase of skaffold

User facing changes (remove if N/A)
Users can now see TaskEvents for Test phase using the skaffold API V2

[tejal29]

We should consider adding integration tests for V2 events and Test events

[codecov]

Codecov Report

Merging #5814 (bd32c2b) into master (8efc9ef) will decrease coverage by 0.01%.
The diff coverage is 82.63%.

@@            Coverage Diff             @@
##           master    #5814      +/-   ##
==========================================
- Coverage   71.00%   70.99%   -0.02%     
==========================================
  Files         438      439       +1     
  Lines       16497    16506       +9     
==========================================
+ Hits        11714    11718       +4     
- Misses       3921     3924       +3     
- Partials      862      864       +2     

Impacted Files	Coverage Δ
cmd/skaffold/app/cmd/apply.go	25.00% <0.00%> (ø)
cmd/skaffold/app/cmd/delete.go	57.14% <0.00%> (ø)
cmd/skaffold/app/cmd/deploy.go	56.52% <0.00%> (ø)
cmd/skaffold/app/cmd/filter.go	25.58% <0.00%> (ø)
cmd/skaffold/app/cmd/find_configs.go	48.48% <0.00%> (ø)
cmd/skaffold/app/cmd/generate_pipeline.go	61.53% <0.00%> (ø)
cmd/skaffold/app/cmd/render.go	40.74% <0.00%> (ø)
cmd/skaffold/app/cmd/runner.go	58.49% <0.00%> (ø)
cmd/skaffold/app/cmd/test.go	46.66% <0.00%> (ø)
cmd/skaffold/app/cmd/util.go	77.77% <ø> (ø)
... and 133 more

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