Reduce the number of calls to the catalog API endpoint

Instead, get the list of existing locations only once from the API

plugins/bulk-import-backend/src/helpers/catalogInfoGenerator.ts

@@ -87,4 +87,20 @@ ${jsYaml.dump(generatedEntity.entity)}`,
   getCatalogUrl(repoUrl: string, defaultBranch: string = 'main'): string {
     return `${repoUrl}/blob/${defaultBranch}/catalog-info.yaml`;
   }
+
+  async listCatalogUrlLocations(): Promise<string[]> {
+    const response = await fetch(
+        `${await this.discovery.getBaseUrl('catalog')}/locations`,
+        {
+          headers: {
+            'Accept': 'application/json',
+          },
+          method: 'GET',
+        },
+    );
+    const locations = (await response.json()) as {data: {id: string, target: string, type: string}}[];
+    return locations
+        .filter(location => location.data.type === 'url')
+        .map(location => location.data.target);
+  }
 }