Add ocm package

internal/service/ocm/ocm.go

@@ -0,0 +1,33 @@
+package ocm
+
+import (
+	"fmt"
+
+	commonerrors "github.com/kyma-project/modulectl/internal/common/errors"
+)
+
+type ModuleDefinition struct {
+	Name          string
+	Version       string
+	SchemaVersion string
+
+	// TODO: Define Layer struct based on the new ocm and remember to add the raw-manifest layer
+	// Layers []Layer
+
+}
+
+func (d *ModuleDefinition) ValidateModuleDefinition() error {
+	if d.Name == "" {
+		return fmt.Errorf("%w: module name must not be empty", commonerrors.ErrInvalidArg)
+	}
+
+	if d.Version == "" {
+		return fmt.Errorf("%w: module version must not be empty", commonerrors.ErrInvalidArg)
+	}
+
+	if d.SchemaVersion == "" {
+		return fmt.Errorf("%w: module schema version must not be empty", commonerrors.ErrInvalidArg)
+	}
+
+	return nil
+}