fix: remove obsolete package and fix tests

packages/app/package.json

@@ -18,7 +18,6 @@
     "@material-ui/core": "^4.9.1",
     "@material-ui/icons": "^4.9.1",
     "@material-ui/lab": "4.0.0-alpha.45",
-    "@types/http-proxy": "^1.17.4",
     "prop-types": "^15.7.2",
     "react": "^16.12.0",
     "react-dom": "^16.12.0",

plugins/catalog-backend/src/database/Database.ts

@@ -14,9 +14,9 @@
  * limitations under the License.
  */
 
-import { NotFoundError } from '@backstage/backend-common';
 import Knex from 'knex';
 import { v4 as uuidv4 } from 'uuid';
+import { NotFoundError } from '../../../../packages/backend-common/src/errors';
 import {
   AddDatabaseComponent,
   AddDatabaseLocation,