Refactor runID usage, populate runID field in metadata event

[MarlonGamez]

Related: #5843

Description
This PR refactors the runID variable to be passed through the main RunContext of skaffold, rather than used through a package variable. It also populates the runID field in the metadata event that gets sent through the event API.

[codecov]

Codecov Report

Merging #6033 (eb10c2f) into master (5c2e24c) will decrease coverage by 0.02%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #6033      +/-   ##
==========================================
- Coverage   70.77%   70.74%   -0.03%     
==========================================
  Files         462      464       +2     
  Lines       17897    17928      +31     
==========================================
+ Hits        12666    12684      +18     
- Misses       4299     4313      +14     
+ Partials      932      931       -1     

Impacted Files	Coverage Δ
pkg/skaffold/deploy/label/labeller.go	68.75% <ø> (ø)
pkg/skaffold/runner/v1/new.go	64.03% <ø> (+0.17%)	⬆️
pkg/skaffold/event/v2/event.go	79.83% <100.00%> (ø)
pkg/skaffold/event/v2/metadata.go	88.73% <100.00%> (+0.16%)	⬆️
pkg/skaffold/runner/runcontext/context.go	84.50% <100.00%> (+0.33%)	⬆️
pkg/skaffold/deploy/deploy_mux.go	70.73% <0.00%> (-5.59%)	⬇️
...skaffold/kubernetes/debugging/container_manager.go	50.00% <0.00%> (-1.86%)	⬇️
pkg/skaffold/docker/parse.go	86.19% <0.00%> (-0.96%)	⬇️
pkg/skaffold/deploy/kustomize/kustomize.go	75.34% <0.00%> (-0.36%)	⬇️
pkg/skaffold/deploy/helm/deploy.go	78.92% <0.00%> (-0.25%)	⬇️
... and 17 more

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