[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/auth/sign-in-up/components/SignInUpWithCredentials.tsx

@@ -14,8 +14,8 @@ import styled from '@emotion/styled';
 import { useMemo, useState } from 'react';
 import { useFormContext } from 'react-hook-form';
 import { useRecoilValue } from 'recoil';
+import { isDefined } from 'twenty-shared';
 import { Loader, MainButton } from 'twenty-ui';
-import { isDefined } from '~/utils/isDefined';
 
 const StyledForm = styled.form`
   align-items: center;