Implement podman support for devfile/registry-operator

[Jdubrick]

/kind user-story

Which area this user story is related to?

/area registry

User Story

Issue opened as a result of #1334 for implementing podman support across our repositories.

As a contributor I want to be able to run the build scripts using podman, so that I can develop for devfile with the use of podman instead of docker.

The registry-operator repository uses a Makefile to run scripts. Possible solutions to this issue could be to add podman support scripts to the Makefile or reference the setenv.sh script in https://github.com/devfile/registry-support

Acceptance Criteria

• Implement podman support for devfile/registry-operator
• Update documentation to reflect changes in the build/deploy process.
• Sufficiently test changes made.

[Jdubrick]

Created PR: devfile/registry-operator#61