Date filter improvements (#5917) (#7196)

Solves issue #5917.

This PR is now ready for the first review!

Filters do not fully work yet, there's a problem applying multiple
filters like the following:

```
{
  and: [
    {
      [correspondingField.name]: {
        gte: start.toISOString(),
      } as DateFilter,
    },
    {
      [correspondingField.name]: {
        lte: end.toISOString(),
      } as DateFilter,
    },
  ],
}
```

I'll do my best to dig into it tonight!

---------

Co-authored-by: Félix Malfait <felix@twenty.com>

packages/twenty-server/src/engine/api/graphql/graphql-query-runner/graphql-query-parsers/graphql-query.parser.ts

@@ -62,9 +62,9 @@ export class GraphqlQueryParser {
     return queryBuilder;
   }
 
-  private checkForDeletedAtFilter(
+  private checkForDeletedAtFilter = (
     filter: FindOptionsWhere<ObjectLiteral> | FindOptionsWhere<ObjectLiteral>[],
-  ): boolean {
+  ): boolean => {
     if (Array.isArray(filter)) {
       return filter.some((subFilter) =>
         this.checkForDeletedAtFilter(subFilter),
@@ -86,7 +86,7 @@ export class GraphqlQueryParser {
     }
 
     return false;
-  }
+  };
 
   applyOrderToBuilder(
     queryBuilder: SelectQueryBuilder<any>,