e2e: cleanup TestGlobalHelp() to be less brittle
e2e: cleanup TestGlobalHelp() to be less brittle

- remove check for "A self-sufficient runtime for containers"; really
  not important to check for.
- don't make the checks positional (just match that we find them, and
  that we don't find them multiple times)
- account for leading whitespace to change instead of hard-coding the
  number of spaces before output.
- change the badopt check; I think it should be sufficient to check
  that the bad option was printed and that "run --help" output is
  printed.

Signed-off-by: Sebastiaan van Stijn <64b2b6d12bfe4baae7dad3d018f8cbf6b0e7a044@gone.nl>

thaJeztah/cli,thaJeztah/cli,docker/cli,cpuguy83/cli,cpuguy83/cli,docker/cli