[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/ui/layout/show-page/components/ShowPageSummaryCard.tsx

@@ -7,11 +7,11 @@ import Skeleton, { SkeletonTheme } from 'react-loading-skeleton';
 import { AppTooltip, Avatar, AvatarType, IconComponent } from 'twenty-ui';
 import { v4 as uuidV4 } from 'uuid';
 
+import { isDefined } from 'twenty-shared';
 import {
   beautifyExactDateTime,
   beautifyPastDateRelativeToNow,
 } from '~/utils/date-utils';
-import { isDefined } from '~/utils/isDefined';
 
 type ShowPageSummaryCardProps = {
   avatarPlaceholder: string;