Add Notarius configuration and extraction source policy

internal/artifacts/artifact_resolver.go

@@ -144,6 +144,22 @@ func ConfiguredArtifactName(source string) (string, bool) {
 	return artifactpolicy.ParseConfiguredSource(source)
 }
 
+// ExtractionArtifactSourceID returns narratio.extraction.<name> for a configured key.
+func ExtractionArtifactSourceID(key string) string {
+	return artifactpolicy.ExtractionSourceID(key)
+}
+
+// IsExtractionArtifactSource reports whether source is narratio.extraction.<name>.
+func IsExtractionArtifactSource(source string) bool {
+	_, ok := artifactpolicy.ParseExtractionSource(source)
+	return ok
+}
+
+// ExtractionArtifactName extracts <name> from narratio.extraction.<name>.
+func ExtractionArtifactName(source string) (string, bool) {
+	return artifactpolicy.ParseExtractionSource(source)
+}
+
 // IsPreviousSessionArtifactSource returns true when source is narratio.previous_session.artifact.<name>.
 func IsPreviousSessionArtifactSource(source string) bool {
 	_, ok := artifactpolicy.ParsePreviousSessionSource(source)