Fix note/task target creation to support morph relations (#17734)

## Overview
Fixes the `unknown fields opportunityId in objectMetadataItem
noteTarget` error when creating notes/tasks from record pages (like the
Notes/Tasks tab on an opportunity).

## Root Cause
The `useOpenCreateActivityDrawer` hook was not handling `MORPH_RELATION`
field types:

1. Code only checked `field.relation` (which is populated for `RELATION`
type fields)
2. When `field.relation` was undefined (because the field is
`MORPH_RELATION`), it fell back to the old naming convention (e.g.,
`opportunityId`)
3. But after the morph migration, the columns are named differently
(e.g., `targetOpportunityId`)

This caused the error on both new workspaces (which are created with
morph relations from the start) and existing workspaces that ran the
migration.

## Solution
Use the existing `findTargetFieldInfo()` utility which properly handles
both `RELATION` and `MORPH_RELATION` field types by:
- Checking `morphRelations` for morph fields and computing the correct
field name
- Checking `relation` for regular relation fields
- Returning the correct `joinColumnName` for each case

This utility is already used elsewhere in the codebase (e.g., in
junction field handling) and is the cleanest solution.

packages/twenty-front/src/modules/activities/hooks/useOpenCreateActivityDrawer.ts

@@ -15,7 +15,7 @@ import { type TaskTarget } from '@/activities/types/TaskTarget';
 import { useOpenRecordInCommandMenu } from '@/command-menu/hooks/useOpenRecordInCommandMenu';
 import { useObjectMetadataItems } from '@/object-metadata/hooks/useObjectMetadataItems';
 import { useCreateOneRecord } from '@/object-record/hooks/useCreateOneRecord';
-import { isDefined } from 'twenty-shared/utils';
+import { findTargetFieldInfo } from '@/object-record/record-field/ui/utils/junction/findTargetFieldInfo';
 
 export const useOpenCreateActivityDrawer = ({
   activityObjectNameSingular,
@@ -90,17 +90,15 @@ export const useOpenCreateActivityDrawer = ({
           item.nameSingular === targetableObjects[0].targetObjectNameSingular,
       );
 
-      const targetField = activityTargetObjectMetadata?.fields.find(
-        (field) =>
-          field.relation?.targetObjectMetadata.id ===
-          targetObjectMetadataItem?.id,
+      const targetFieldInfo = findTargetFieldInfo(
+        activityTargetObjectMetadata?.fields ?? [],
+        targetObjectMetadataItem?.id ?? '',
+        objectMetadataItems,
       );
 
-      const joinColumnName = targetField?.settings?.joinColumnName;
-
-      const targetableObjectRelationIdName = isDefined(joinColumnName)
-        ? joinColumnName
-        : `${targetableObjects[0].targetObjectNameSingular}Id`;
+      const targetableObjectRelationIdName =
+        targetFieldInfo?.joinColumnName ??
+        `${targetableObjects[0].targetObjectNameSingular}Id`;
 
       await createOneActivityTarget({
         ...(activityObjectNameSingular === CoreObjectNameSingular.Task