Fix timeline activities display (#16880)

Fixes https://github.com/twentyhq/twenty/issues/16809

# Introduction
Front was expected timeline activities field to be relation and not
morph relation

Also fixed the new v2 workspace creation that had a bug in the
createStandardRelation util ( it's not in production yet so everything's
fine )

packages/twenty-front/src/modules/activities/timeline-activities/hooks/useTimelineActivities.ts

@@ -31,8 +31,12 @@ export const useTimelineActivities = (
 
   const hasTimelineActivityField = timelineActivityMetadata.fields.some(
     (field) =>
-      field.relation?.targetObjectMetadata?.nameSingular ===
-      targetableObject.targetObjectNameSingular,
+      isDefined(field.morphRelations) &&
+      field.morphRelations.some(
+        (morphRelation) =>
+          morphRelation.targetObjectMetadata?.nameSingular ===
+          targetableObject.targetObjectNameSingular,
+      ),
   );
 
   const { recordGqlFields: depthOneRecordGqlFields } =

packages/twenty-server/src/engine/workspace-manager/twenty-standard-application/utils/field-metadata/create-standard-relation-field-flat-metadata.util.ts

@@ -3,7 +3,7 @@ import {
   type FieldMetadataDefaultOption,
   type FieldMetadataDefaultValueForAnyType,
   type FieldMetadataSettings,
-  FieldMetadataType,
+  type FieldMetadataType,
 } from 'twenty-shared/types';
 
 import { type FlatFieldMetadata } from 'src/engine/metadata-modules/flat-field-metadata/types/flat-field-metadata.type';
@@ -70,6 +70,7 @@ export const createStandardRelationFieldFlatMetadata = <
     settings,
     options: fieldOptions = null,
     morphId,
+    type,
   },
   standardObjectMetadataRelatedEntityIds,
   twentyStandardApplicationId,
@@ -89,7 +90,7 @@ export const createStandardRelationFieldFlatMetadata = <
     applicationId: twentyStandardApplicationId,
     workspaceId,
     objectMetadataId: standardObjectMetadataRelatedEntityIds[objectName].id,
-    type: FieldMetadataType.RELATION,
+    type,
     name: fieldName.toString(),
     label,
     description,