Ensure arguments are consistent across commands

[bryanl]

Arguments should be consistent across commands. A potential list:

• bundle directories
• verbose mode
• dry run mode
• images
• artifact bundle references

[glyn]

Also, we might want to reorganise the commands a bit while we are at it. Currently, sheaf archive list-images takes a --bundle-path flag, in which case it's not operating on an archive at all. This could perhaps be split out into a new top-level command.