Add "search" to reserved metadata name keywords (#19181)

## Summary
- Adds `search` and `searches` to the `RESERVED_METADATA_NAME_KEYWORDS`
list in `twenty-shared`
- Prevents users from creating custom objects named "search", which
collides with the core `search` GraphQL resolver

packages/twenty-shared/src/metadata/constants/reserved-metadata-name-keywords.constant.ts

@@ -62,4 +62,6 @@ export const RESERVED_METADATA_NAME_KEYWORDS = [
   'relation',
   'relations',
   'aggregate',
+  'search',
+  'searches',
 ];