Add persistent volumes info to storage class submenu (#2160)

Signed-off-by: vshakirova <vshakirova@mirantis.com>

src/renderer/api/endpoints/persistent-volume.api.ts

@@ -70,6 +70,10 @@ export class PersistentVolume extends KubeObject {
   getClaimRefName(): string {
     return this.spec.claimRef?.name ?? "";
   }
+
+  getStorageClassName() {
+    return this.spec.storageClassName || "";
+  }
 }
 
 export const persistentVolumeApi = new KubeApi({