[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/support/hooks/useSupportChat.ts

@@ -5,7 +5,7 @@ import { useIsPrefetchLoading } from '@/prefetch/hooks/useIsPrefetchLoading';
 import { isNonEmptyString } from '@sniptt/guards';
 import { useCallback, useEffect, useState } from 'react';
 import { useRecoilValue } from 'recoil';
-import { isDefined } from 'twenty-ui';
+import { isDefined } from 'twenty-shared';
 import { User, WorkspaceMember } from '~/generated-metadata/graphql';
 
 const insertScript = ({