Turn the hack/e2e.go commands into standalone scripts.
Turn the hack/e2e.go commands into standalone scripts.

This gets rid of bashWrap() and of running bash -s passing it a script
on stdin. Also get rid of most of the runBash*() helpers.

In particular, `go run hack/e2e.go -build` will now work when it needs
to ask whether it is OK to download a large docker image, it used to
fail since stdin was not available for the bash script using the `read`
command.

Tested by running a full `hack/e2e-test.sh` run including the build
stage without the docker image loaded, which used to fail before this
change.

shyamjvs/test-infra,rmmh/kubernetes-test-infra,pwittrock/test-infra,cblecker/test-infra,krzyzacy/test-infra,kargakis/test-infra,krzyzacy/test-infra,dims/test-infra,gmarek/test-infra,dims/test-infra,dchen1107/test-infra,jlowdermilk/test-infra,ixdy/kubernetes-test-infra,grodrigues3/test-infra,rmmh/kubernetes-test-infra,kubernetes/test-infra,lavalamp/test-infra,spxtr/test-infra,foxish/test-infra,lavalamp/test-infra,krzyzacy/test-infra,kargakis/test-infra,krzyzacy/test-infra,spxtr/test-infra,kargakis/test-infra,kubernetes/test-infra,shashidharatd/test-infra,ixdy/kubernetes-test-infra,kargakis/test-infra,kewu1992/test-infra,dims/test-infra,fejta/test-infra,cjwagner/test-infra,cjwagner/test-infra,mindprince/test-infra,krzyzacy/test-infra,kubernetes/test-infra,shashidharatd/test-infra,piosz/test-infra,piosz/test-infra,madhusudancs/test-infra,jessfraz/test-infra,rmmh/kubernetes-test-infra,brahmaroutu/test-infra,cblecker/test-infra,piosz/test-infra,kewu1992/test-infra,pwittrock/test-infra,michelle192837/test-infra,mikedanese/test-infra,dchen1107/test-infra,madhusudancs/test-infra,mtaufen/test-infra,cjwagner/test-infra,brahmaroutu/test-infra,cblecker/test-infra,cblecker/test-infra,brahmaroutu/test-infra,gmarek/test-infra,piosz/test-infra,spxtr/test-infra,michelle192837/test-infra,abgworrall/test-infra,krousey/test-infra,brahmaroutu/test-infra,lavalamp/test-infra,madhusudancs/test-infra,mtaufen/test-infra,jessfraz/test-infra,lavalamp/test-infra,dchen1107/test-infra,kargakis/test-infra,shyamjvs/test-infra,michelle192837/test-infra,pwittrock/test-infra,dchen1107/test-infra,rmmh/kubernetes-test-infra,foxish/test-infra,cjwagner/test-infra,monopole/test-infra,mindprince/test-infra,gmarek/test-infra,jessfraz/test-infra,ixdy/kubernetes-test-infra,BenTheElder/test-infra,brahmaroutu/test-infra,shyamjvs/test-infra,abgworrall/test-infra,kewu1992/test-infra,fejta/test-infra,gmarek/test-infra,grodrigues3/test-infra,BenTheElder/test-infra,jlowdermilk/test-infra,monopole/test-infra,brahmaroutu/test-infra,lavalamp/test-infra,shyamjvs/test-infra,mtaufen/test-infra,krousey/test-infra,abgworrall/test-infra,mtaufen/test-infra,kubernetes/test-infra,jessfraz/test-infra,spxtr/test-infra,rmmh/kubernetes-test-infra,monopole/test-infra,jessfraz/test-infra,nlandolfi/test-infra-1,mikedanese/test-infra,fejta/test-infra,madhusudancs/test-infra,jessfraz/test-infra,cblecker/test-infra,kewu1992/test-infra,abgworrall/test-infra,mindprince/test-infra,monopole/test-infra,shashidharatd/test-infra,michelle192837/test-infra,lavalamp/test-infra,krousey/test-infra,cjwagner/test-infra,nlandolfi/test-infra-1,dims/test-infra,krousey/test-infra,kargakis/test-infra,mikedanese/test-infra,pwittrock/test-infra,kubernetes/test-infra,fejta/test-infra,ixdy/kubernetes-test-infra,BenTheElder/test-infra,grodrigues3/test-infra,abgworrall/test-infra,shyamjvs/test-infra,ixdy/kubernetes-test-infra,nlandolfi/test-infra-1,foxish/test-infra,shyamjvs/test-infra,madhusudancs/test-infra,kewu1992/test-infra,BenTheElder/test-infra,grodrigues3/test-infra,shashidharatd/test-infra,foxish/test-infra,michelle192837/test-infra,mikedanese/test-infra,dims/test-infra,dchen1107/test-infra,jlowdermilk/test-infra,nlandolfi/test-infra-1,cjwagner/test-infra,shashidharatd/test-infra,pwittrock/test-infra,mindprince/test-infra,piosz/test-infra,monopole/test-infra,michelle192837/test-infra,grodrigues3/test-infra,BenTheElder/test-infra,jlowdermilk/test-infra,monopole/test-infra,kubernetes/test-infra,foxish/test-infra,fejta/test-infra,mtaufen/test-infra,fejta/test-infra,krzyzacy/test-infra,nlandolfi/test-infra-1,spxtr/test-infra,BenTheElder/test-infra,dims/test-infra,cblecker/test-infra,mindprince/test-infra,jlowdermilk/test-infra,mikedanese/test-infra,jlowdermilk/test-infra,gmarek/test-infra,krousey/test-infra