Add rm and rmi commands

[ozoder]

Add rm and rmi commands for images/containers removal. Both commands take ID or name as an argument and if the specified image/container was created by fedora-toolbox, it's removed.

Both commands have two flags: --all and --force. With the --all flag, the argument is not needed, as the command tries to remove all fedora-toolbox images/containers. The --force flag just runs force removal (i.e podman rm/rmi --force )

[debarshiray]

The branch needs to be rebased on top of master. Some quick comments:

[ozoder]

I've added the possibility to remove multiple images/containers at once. Toolbox rm and rmi commands can now take more than one name/ID, the same way podman rm and rmi commands do it.

[matthiasclasen]

I think long names like 'delete' and 'delete-image' would go better with the existing create/list/enter

[debarshiray]

I think long names like 'delete' and 'delete-image' would go better with the existing create/list/enter

I have been going back and forth on that myself. We can definitely add the longer names as aliases. eg., ls as a shorter alias for list seems very reasonable.

At the same time toolbox rm is such a very thin wrapper around podman rm that seems sensible to use the podman nomenclature for the short form. It also conveniently matches the rm(1) command.

[debarshiray]

Here's some feedback after using this branch for a few days:

It mostly looks good. We now have man pages, so we need to add those for these new commands, and we need to make the commands work inside a toolbox container.

Rest of the details below:

[debarshiray]

I took the liberty to address the above nits.