Emit TaskEvents Protos for PortForwarding

[MarlonGamez]

Fixes: #5422
Related: #5368 #5422

Description
Emit taskevent protos on v2 endpoints

User facing changes (remove if N/A)
Users can now use the v2 event API to see the start, end, or failure of the portforward phase

[codecov]

Codecov Report

Merging #5689 (2d4618e) into master (21debe2) will increase coverage by 0.09%.
The diff coverage is 72.72%.

@@            Coverage Diff             @@
##           master    #5689      +/-   ##
==========================================
+ Coverage   70.74%   70.84%   +0.09%     
==========================================
  Files         421      421              
  Lines       16037    16043       +6     
==========================================
+ Hits        11346    11366      +20     
+ Misses       3858     3845      -13     
+ Partials      833      832       -1     

Impacted Files	Coverage Δ
cmd/skaffold/app/cmd/flags.go	89.02% <ø> (ø)
pkg/skaffold/config/options.go	100.00% <ø> (ø)
...affold/kubernetes/portforward/forwarder_manager.go	52.38% <0.00%> (+19.04%)	⬆️
pkg/skaffold/runner/portforwarder.go	22.22% <ø> (+2.22%)	⬆️
pkg/skaffold/runner/runner.go	0.00% <ø> (ø)
pkg/skaffold/runner/build_deploy.go	69.23% <60.00%> (ø)
pkg/skaffold/runner/dev.go	71.82% <62.50%> (ø)
pkg/skaffold/runner/deploy.go	53.60% <80.00%> (ø)
pkg/skaffold/build/builder_mux.go	48.78% <84.61%> (+4.04%)	⬆️
pkg/skaffold/event/v2/event.go	73.73% <100.00%> (ø)
... and 9 more

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