Add pod checks

[tejal29]

Should merge after #3938
Fixes: #3915
Relates to: #3739, #3813

Description
In this PR, i am trying to move parts of #3917

User facing changes (remove if N/A)
No user facing changes for skaffold users.

Follow-up Work (remove if N/A)

• Hook up pod health checker.
• Make status check interruptible.

[codecov]

Codecov Report

Merging #3952 into master will increase coverage by 0.01%.
The diff coverage is n/a.

Impacted Files	Coverage Δ
pkg/skaffold/debug/transform_python.go	84.33% <0.00%> (-0.37%)	⬇️
pkg/skaffold/debug/transform_go.go	85.86% <0.00%> (-0.31%)	⬇️
pkg/skaffold/debug/transform_nodejs.go	77.67% <0.00%> (-0.20%)	⬇️
pkg/skaffold/debug/transform_jvm.go	94.68% <0.00%> (-0.06%)	⬇️
pkg/skaffold/debug/transform.go	89.37% <0.00%> (ø)
pkg/skaffold/schema/versions.go	75.00% <0.00%> (ø)
pkg/skaffold/deploy/kubectl/visitor.go	93.54% <0.00%> (ø)
pkg/skaffold/errors/errors.go	100.00% <0.00%> (ø)
pkg/skaffold/schema/v2beta1/config.go	100.00% <0.00%> (ø)
pkg/skaffold/schema/v2beta1/upgrade.go	77.77% <0.00%> (ø)
... and 1 more