Add new database connection (#4837)

Closes https://github.com/twentyhq/twenty/issues/4555

<img width="593" alt="Capture d’écran 2024-04-05 à 11 54 28"
src="https://github.com/twentyhq/twenty/assets/22936103/e6021417-bc78-460b-adf6-834330bbd894">

Connect the existing for with the backend so we can now create database
connections.

---------

Co-authored-by: Thomas Trompette <thomast@twenty.com>

packages/twenty-front/src/modules/databases/utils/getForeignDataWrapperType.ts

@@ -0,0 +1,8 @@
+export const getForeignDataWrapperType = (databaseKey: string) => {
+  switch (databaseKey) {
+    case 'postgresql':
+      return 'postgres_fdw';
+    default:
+      return null;
+  }
+};