Worker/koji-finalize: import osbuild manifest and log to Koji build

Import osbuild manifest and build log to the Koji build as outputs. Also
note the respective filenames in the image output extra metadata.

Note that the osbuild manifest is imported as a log file for now. Koji
has very limited set of output types defined and I still need to
determine the best way to use a custom output type in Koji instances (as
other content generators do).

Signed-off-by: Tomáš Hozza <thozza@redhat.com>

cmd/osbuild-koji/main.go

@@ -99,7 +99,7 @@ func main() {
 			Type:         koji.BuildOutputTypeImage,
 			RPMs:         []rpmmd.RPM{},
 			Extra: &koji.BuildOutputExtra{
-				Image: koji.ImageExtraInfo{
+				ImageOutput: koji.ImageExtraInfo{
 					Arch:     arch,
 					BootMode: distro.BOOT_NONE.String(), // TODO: put the correct boot mode here
 				},