Feat/disable flexible backend (#1673)

* wip: refacto and start creating custom resolver

* feat: findMany & findUnique of a custom entity

* feat: wip pagination

* feat: initial metadata migration

* feat: universal findAll with pagination

* fix: clean small stuff in pagination

* fix: test

* fix: miss file

* feat: rename custom into universal

* feat: enable/disable flexible backend from env

---------

Co-authored-by: Charles Bochet <charles@twenty.com>
Co-authored-by: Charles Bochet <charlesBochet@users.noreply.github.com>

server/src/core/client-config/client-config.entity.ts

@@ -44,6 +44,9 @@ export class ClientConfig {
   @Field(() => Boolean)
   debugMode: boolean;
 
+  @Field(() => Boolean)
+  flexibleBackendEnabled: boolean;
+
   @Field(() => Support)
   support: Support;
 }