internal/target: add OCI object storage target

Uploads an OCI image to OCI object storage, and generates a
pre-authenticated request for the object, which can be used to import it
into custom images.

internal/target/target.go

@@ -87,6 +87,8 @@ func (target *Target) UnmarshalJSON(data []byte) error {
 		options = new(VMWareTargetOptions)
 	case TargetNameOCI:
 		options = new(OCITargetOptions)
+	case TargetNameOCIObjectStorage:
+		options = new(OCIObjectStorageTargetOptions)
 	case TargetNameContainer:
 		options = new(ContainerTargetOptions)
 	case TargetNameWorkerServer:
@@ -246,6 +248,18 @@ func (target Target) MarshalJSON() ([]byte, error) {
 			}
 			rawOptions, err = json.Marshal(compat)
 
+		case *OCIObjectStorageTargetOptions:
+			type compatOptionsType struct {
+				*OCIObjectStorageTargetOptions
+				// Deprecated: `Filename` is now set in the target itself as `ExportFilename`, not in its options.
+				Filename string `json:"filename"`
+			}
+			compat := compatOptionsType{
+				OCIObjectStorageTargetOptions: t,
+				Filename:                      target.OsbuildArtifact.ExportFilename,
+			}
+			rawOptions, err = json.Marshal(compat)
+
 		case *ContainerTargetOptions:
 			type compatOptionsType struct {
 				*ContainerTargetOptions