Use common return value pattern in AppstoreModel

dashboard/src/views/AppstoreView.vue

@@ -53,8 +53,25 @@ function onInstall(app) {
   appInstallDialog.value.open(app);
 }
 
+async function getAppList() {
+  const [error, result] = await appstoreModel.list();
+  if (error) return console.error(error);
+
+  apps.value = result;
+}
+
+async function getApp(id, version = '') {
+  const [error, result] = await appstoreModel.get(id, version);
+  if (error) {
+    console.error(error);
+    return null;
+  }
+
+  return result;
+}
+
 onMounted(async () => {
-  apps.value = await appstoreModel.list();
+  await getAppList();
   ready.value = true;
 
   const query = window.location.hash.slice('#/appstore/'.length);
@@ -62,7 +79,7 @@ onMounted(async () => {
     const appId = query.split('?')[0];
     const version = query.slice(query.indexOf('version=')+'version='.length);
 
-    const app = await appstoreModel.get(appId, version);
+    const app = await getApp(appId, version);
     if (app) {
       appInstallDialog.value.open(app);
     } else {
@@ -72,7 +89,7 @@ onMounted(async () => {
     searchInput.value.$el.focus();
   }
 
-  proxyApp.value = await appstoreModel.get(PROXY_APP_ID);
+  proxyApp.value = await getApp(PROXY_APP_ID);
 });
 
 </script>