wwctl image completions and arguments

Signed-off-by: Jonathon Anderson <janderson@ciq.com>

internal/app/wwctl/image/copy/root.go

@@ -13,7 +13,7 @@ var (
 		Short:                 "Copy an existing image",
 		Long:                  "This command will duplicate an imported image.",
 		RunE:                  CobraRunE,
-		Args:                  cobra.MinimumNArgs(2),
+		Args:                  cobra.ExactArgs(2),
 		ValidArgsFunction: func(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {
 			if len(args) != 0 {
 				return nil, cobra.ShellCompDirectiveNoFileComp