add option to use executables from local container instead of local system

[serhei]

This would allow oc-inject to use executables that match the distribution within the container image (instead of hoping the local development environment's executables will work within the container environment).

Requires assembling a suite of images for different OpenShift environments, along the lines of support-tools https://access.redhat.com/containers/#/registry.access.redhat.com/rhel8/support-tools -- could be done by collecting a set of Dockerfiles and building them locally with Podman, or by uploading images to a registry.

[serhei]

Brainstorming how this feature should ideally work. The workflow could actually be as follows, e.g. for Java support:

• Take the same container image as what's running in OpenShift.
• Use as the base image for a local container build e.g. FROM my-container-image; RUN yum install java-1.8.0-openjdk-devel -> producing my-debug-image
• oc-inject --from-podman=my-debug-image -it my-container -- jstack 1 (oc-inject uses something like podman run to run ldd in the container image, then podman mount to extract the files)

If these steps are well-documented, it would reduce the need for do-everything 'support-tools' type images. Perhaps the first two steps could be automated with a separate command, or turned into an oc-inject command line option:

oc-inject --from-openshift=my-container+java-1.8.0-openjdk -it my-container -- jstack 1
oc-inject -it my-container+java-1.8.0-openjdk -- jstack 1