Null equivalence - Fix (#16050)

@charlesBochet 
In workflow codebase, NULL (instead of empty object) is expected on
workflow version object step field, when a new workflow is created for
example.
(packages/twenty-front/src/modules/workflow/workflow-diagram/utils/generateWorkflowDiagram.ts
- 42)
This case is not isolated and it creates many issues.

We decided to format NULL value to equivalent (empty string for text
field, empty object for raw_json) but it seems it complicates the dev x.

To unlock @Devessier I prefer revert the logic, the time we discuss how
to solve this cases.

packages/twenty-server/src/engine/twenty-orm/utils/format-result.util.ts

@@ -10,7 +10,6 @@ import { isDefined } from 'twenty-shared/utils';
 import {
   DEFAULT_ARRAY_FIELD_NULL_EQUIVALENT_VALUE,
   DEFAULT_COMPOSITE_FIELDS_NULL_EQUIVALENT_VALUE,
-  DEFAULT_RAW_JSON_FIELD_NULL_EQUIVALENT_VALUE,
   DEFAULT_TEXT_FIELD_NULL_EQUIVALENT_VALUE,
 } from 'src/engine/api/common/common-args-processors/data-arg-processor/constants/null-equivalent-values.constant';
 import { type FieldMetadataEntity } from 'src/engine/metadata-modules/field-metadata/field-metadata.entity';
@@ -199,10 +198,6 @@ function formatFieldMetadataValue(
       return DEFAULT_ARRAY_FIELD_NULL_EQUIVALENT_VALUE;
     }
 
-    if (fieldMetadataType === FieldMetadataType.RAW_JSON) {
-      return DEFAULT_RAW_JSON_FIELD_NULL_EQUIVALENT_VALUE;
-    }
-
     if (fieldMetadataType === FieldMetadataType.TEXT) {
       return DEFAULT_TEXT_FIELD_NULL_EQUIVALENT_VALUE;
     }