Adding events for Test phase

[PriyaModali]

Fixes: #5539

Description
Adding events for Test phase

Skaffold currently doesn't log events for test phase progress.
With this change the tests log test progress events .

Related:
#5333

Example

The functionality can be tested using the example in the integration tests:
skaffold/integration/examples/test-events-test

[codecov]

Codecov Report

Merging #5573 (04ab4fa) into master (e74d752) will increase coverage by 0.03%.
The diff coverage is 90.00%.

@@            Coverage Diff             @@
##           master    #5573      +/-   ##
==========================================
+ Coverage   71.05%   71.08%   +0.03%     
==========================================
  Files         402      402              
  Lines       15096    15145      +49     
==========================================
+ Hits        10726    10766      +40     
- Misses       3577     3586       +9     
  Partials      793      793              

Impacted Files	Coverage Δ
pkg/skaffold/errors/errors.go	91.48% <ø> (+2.12%)	⬆️
pkg/skaffold/instrumentation/export.go	75.55% <0.00%> (-1.72%)	⬇️
pkg/skaffold/event/event.go	91.06% <94.44%> (-0.42%)	⬇️
pkg/skaffold/runner/dev.go	72.22% <100.00%> (+0.17%)	⬆️
pkg/skaffold/test/custom/custom.go	58.94% <100.00%> (+2.76%)	⬆️
pkg/skaffold/test/structure/structure.go	88.13% <100.00%> (+0.63%)	⬆️
pkg/skaffold/util/tar.go	50.66% <0.00%> (-5.34%)	⬇️
pkg/skaffold/docker/parse.go	85.40% <0.00%> (+1.08%)	⬆️

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[gsquared94]

Please address the review comments. Otherwise changes look good.

[PriyaModali]

Please address the review comments. Otherwise changes look good.

Addresses the feedback.

Addresses the feedback.

[gsquared94]

lgtm!