plugins: refactory to use default export for new backend system

Co-authored-by: Fredrik Adelöw <freben@gmail.com>
Co-authored-by: Camila Belo <camilaibs@gmail.com>
Co-authored-by: Johan Haals <johan.haals@gmail.com>
Co-authored-by: Philipp Hugenroth <philipph@spotify.com>
Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>

plugins/search-backend/alpha-api-report.md

@@ -6,7 +6,8 @@
 import { BackendFeature } from '@backstage/backend-plugin-api';
 
 // @alpha
-export const searchPlugin: () => BackendFeature;
+const _default: () => BackendFeature;
+export default _default;
 
 // (No @packageDocumentation comment for this package)
 ```

plugins/search-backend/src/alpha.test.ts

@@ -16,7 +16,7 @@
 
 import { startTestBackend } from '@backstage/backend-test-utils';
 import request from 'supertest';
-import { searchPlugin } from './alpha';
+import searchPlugin from './alpha';
 
 describe('searchPlugin', () => {
   it('should serve search results on query endpoint', async () => {

plugins/search-backend/src/alpha.ts

@@ -75,7 +75,7 @@ class SearchEngineRegistry implements SearchEngineRegistryExtensionPoint {
  * The Search plugin is responsible for starting search indexing processes and return search results.
  * @alpha
  */
-export const searchPlugin = createBackendPlugin({
+export default createBackendPlugin({
   pluginId: 'search',
   register(env) {
     const searchIndexRegistry = new SearchIndexRegistry();