[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-server/src/modules/workflow/workflow-executor/workflow-actions/mail-sender/send-email.workflow-action.ts

@@ -3,6 +3,7 @@ import { Injectable, Logger } from '@nestjs/common';
 import DOMPurify from 'dompurify';
 import { JSDOM } from 'jsdom';
 import { z } from 'zod';
+import { isDefined } from 'twenty-shared';
 
 import { WorkflowAction } from 'src/modules/workflow/workflow-executor/interfaces/workflow-action.interface';
 
@@ -20,7 +21,6 @@ import {
 } from 'src/modules/workflow/workflow-executor/workflow-actions/mail-sender/exceptions/send-email-action.exception';
 import { WorkflowSendEmailActionInput } from 'src/modules/workflow/workflow-executor/workflow-actions/mail-sender/types/workflow-send-email-action-input.type';
 import { WorkflowActionResult } from 'src/modules/workflow/workflow-executor/workflow-actions/types/workflow-action-result.type';
-import { isDefined } from 'src/utils/is-defined';
 
 export type WorkflowSendEmailStepOutputSchema = {
   success: boolean;