subtests.docker_cli.build: Use local busybox if available

Signed-off-by: Lukáš Doktor <ldoktor@redhat.com>
subtests.docker_cli: Add 3 variants with bad Dockerfile

This extension covers `docker build` with `-q`, `--force-rm` and
the behavior when the build fails.

Signed-off-by: Lukáš Doktor <ldoktor@redhat.com>