Add rejection reason to 'unable to find driver' error

[tstromberg]

Our current error message is not as helpful as it could be:

💣 Unable to determine a default driver to use. Try specifying --driver, or see https://minikube.sigs.k8s.io/docs/start/

Here is the new error message this PR proposes:

👎  Unable to pick a default driver. Here is what was considered, in preference order:
    ▪ parallels: Not installed: exec: "docker-machine-driver-parallels": executable file not found in $PATH
    ▪ podman: Not installed: exec: "podman": executable file not found in $PATH
    ▪ vmware: Not installed: exec: "docker-machine-driver-vmware": executable file not found in $PATH
👉  Try specifying a --driver, or see https://minikube.sigs.k8s.io/docs/start/

Solves mysteries such as #7371

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: tstromberg

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[codecov-io]

Codecov Report

Merging #7379 into master will increase coverage by 0.00%.
The diff coverage is 50.00%.

@@           Coverage Diff           @@
##           master    #7379   +/-   ##
=======================================
  Coverage   37.18%   37.19%           
=======================================
  Files         145      145           
  Lines        8836     8851   +15     
=======================================
+ Hits         3286     3292    +6     
- Misses       5154     5162    +8     
- Partials      396      397    +1     

Impacted Files	Coverage Δ
cmd/minikube/cmd/start.go	34.34% <0.00%> (-0.27%)	⬇️
pkg/minikube/out/style.go	91.66% <ø> (ø)
pkg/minikube/registry/global.go	58.69% <ø> (ø)
pkg/minikube/driver/driver.go	64.00% <76.92%> (-0.45%)	⬇️

[sharifelgamal]

I feel like all this logic could be done in one loop instead of two, though I'm not sure if there's a real advantage of either strategy.

Otherwise this PR is great.

[tstromberg]

I agree, but I wasn't smart enough to figure out how without making it overly complicated.

We aren't sure who to pick until the end of the first loop - so no matter what, we need to iterate twice to part out the alternates. I'l leave this for someone better at reasoning about algorithms.

[tstromberg]

/ok-to-test

[minikube-pr-bot]

Error: running mkcmp: exit status 1