Delete: output underlying status failure, better machine function names

[tstromberg]

Old UI if trying to delete a cluster while Docker is down:

❗  Unable to get the status of the minikube cluster.
🔥  Removing /Users/tstromberg/.minikube/machines/minikube ...
💀  Removed all traces of the "minikube" cluster.

It shows a warning, but no information as to why the status failed!

New UI if trying to delete a cluster while Docker is down:

❗  Unable to get host status for "minikube": state: docker inspect -f {{.State.Status}} minikube: Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?: exit status 1
🔥  Removing /Users/tstromberg/.minikube/machines/minikube ...
💀  Removed all traces of the "minikube" cluster.

This also removes some technical debt discovered while trying to improve this message:

• machine.DeleteHost now displays underlying status error in warning
• kic.GetState error now includes command-line and output
• Remove unused machine.List function
• Renamed machine.CheckIfHostExistsAndLoad to machine.LoadHost
• Renamed machine.Load to machine.LoadMachine (repetitive, but clearer vs LoadHost)
• Renamed machine.GetHostStatus to machine.Status
• Renamed machine.IsHostRunning to machine.IsRunning
• Moved CreateSSHShell from machine.go to ssh.go

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: tstromberg

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[tstromberg]

/ok-to-test

[minikube-pr-bot]

Error: running mkcmp: exit status 1

[codecov-io]

Codecov Report

Merging #7043 into master will decrease coverage by 0.35%.
The diff coverage is 34%.

@@            Coverage Diff             @@
##           master    #7043      +/-   ##
==========================================
- Coverage   37.25%   36.89%   -0.36%     
==========================================
  Files         145      146       +1     
  Lines        9114     9099      -15     
==========================================
- Hits         3395     3357      -38     
- Misses       5295     5330      +35     
+ Partials      424      412      -12

Impacted Files	Coverage Δ
cmd/minikube/cmd/config/profile_list.go	3.79% <0%> (ø)	⬆️
cmd/minikube/cmd/ssh.go	7.69% <0%> (ø)	⬆️
pkg/minikube/machine/cache_images.go	0% <0%> (ø)	⬆️
cmd/minikube/cmd/service_list.go	9.37% <0%> (ø)	⬆️
cmd/minikube/cmd/status.go	21.92% <0%> (ø)	⬆️
pkg/minikube/machine/machine.go	0% <0%> (-53.04%)	⬇️
cmd/minikube/cmd/pause.go	7.89% <0%> (ø)	⬆️
cmd/minikube/cmd/dashboard.go	1.63% <0%> (ø)	⬆️
pkg/minikube/cluster/ip.go	0% <0%> (ø)	⬆️
cmd/minikube/cmd/unpause.go	7.5% <0%> (ø)	⬆️
... and 15 more

[medyagh]

Very nice clean up. Like to see more of these. Thank you

[afbjorklund]

@medyagh : this PR broke the master, better to use "lgtm" than merge on these I think ?

https://github.com/kubernetes/minikube/runs/506958518

pkg/minikube/machine/machine.go:82:6: `machineDirs` is unused (deadcode)
func machineDirs(miniHome ...string) (dirs []string, err error) {
     ^
make[1]: *** [lint-ci] Error 1