api: add error message for package without name RHEL-16006

internal/blueprint/blueprint.go

@@ -101,6 +101,18 @@ func (b *Blueprint) Initialize() error {
 		return fmt.Errorf("Error hashing passwords: %s", err.Error())
 	}
 
+	for i, p := range b.Packages {
+		if len(p.Name) == 0 {
+			var errMsg string
+			if len(p.Version) == 0 {
+				errMsg = fmt.Sprintf("Entry #%d has neither version nor name.", i+1)
+			} else {
+				errMsg = fmt.Sprintf("Entry #%d has version '%v' but no name.", i+1, p.Version)
+			}
+			return fmt.Errorf("All package entries need to contain the name of the package. %s", errMsg)
+		}
+	}
+
 	return nil
 }