[CHORE] Avoid isDefined duplicated reference, move it to twenty-shared (#9967)

# Introduction
Avoid having multiple `isDefined` definition across our pacakges
Also avoid importing `isDefined` from `twenty-ui` which exposes a huge
barrel for a such little util function

## In a nutshell
Removed own `isDefined.ts` definition from `twenty-ui` `twenty-front`
and `twenty-server` to move it to `twenty-shared`.
Updated imports for each packages, and added explicit dependencies to
`twenty-shared` if not already in place

Related PR https://github.com/twentyhq/twenty/pull/9941

packages/twenty-front/src/modules/settings/data-model/graph-overview/components/SettingsDataModelOverview.tsx

@@ -20,6 +20,7 @@ import {
   useReactFlow,
 } from '@xyflow/react';
 import { useCallback, useState } from 'react';
+import { isDefined } from 'twenty-shared';
 import {
   Button,
   IconButtonGroup,
@@ -30,7 +31,6 @@ import {
   IconPlus,
   IconX,
 } from 'twenty-ui';
-import { isDefined } from '~/utils/isDefined';
 
 const nodeTypes: NodeTypes = {
   object: SettingsDataModelOverviewObject,

packages/twenty-front/src/modules/settings/data-model/graph-overview/components/SettingsDataModelOverviewEffect.tsx

@@ -5,7 +5,7 @@ import { useEffect } from 'react';
 import { useRecoilValue } from 'recoil';
 
 import { objectMetadataItemsState } from '@/object-metadata/states/objectMetadataItemsState';
-import { isDefined } from '~/utils/isDefined';
+import { isDefined } from 'twenty-shared';
 import { isUndefinedOrNull } from '~/utils/isUndefinedOrNull';
 
 type SettingsDataModelOverviewEffectProps = {