Use twentyORM in Timeline messaging (#6595)

- Remove raw queries and replace them by using `twentyORM`
- Refactor into services and utils

---------

Co-authored-by: Charles Bochet <charles@twenty.com>

packages/twenty-server/src/modules/person/standard-objects/person.workspace-entity.ts

@@ -127,7 +127,7 @@ export class PersonWorkspaceEntity extends BaseWorkspaceEntity {
   })
   @WorkspaceIsSystem()
   @WorkspaceIsNullable()
-  position: number | null;
+  position: number;
 
   @WorkspaceField({
     standardId: PERSON_STANDARD_FIELD_IDS.createdBy,