[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/workflow/utils/assertWorkflowWithCurrentVersionIsDefined.ts

@@ -3,7 +3,7 @@ import {
   WorkflowVersion,
   WorkflowWithCurrentVersion,
 } from '@/workflow/types/Workflow';
-import { isDefined } from 'twenty-ui';
+import { isDefined } from 'twenty-shared';
 
 // eslint-disable-next-line prefer-arrow/prefer-arrow-functions
 export function assertWorkflowWithCurrentVersionIsDefined(

packages/twenty-front/src/modules/workflow/utils/findStepPosition.ts

@@ -1,6 +1,6 @@
 import { WorkflowStep } from '@/workflow/types/Workflow';
 import { TRIGGER_STEP_ID } from '@/workflow/workflow-trigger/constants/TriggerStepId';
-import { isDefined } from 'twenty-ui';
+import { isDefined } from 'twenty-shared';
 
 /**
  * This function returns the reference of the array where the step should be positioned

packages/twenty-front/src/modules/workflow/utils/getStepDefinitionOrThrow.ts

@@ -1,7 +1,7 @@
 import { WorkflowVersion } from '@/workflow/types/Workflow';
 import { findStepPosition } from '@/workflow/utils/findStepPosition';
 import { TRIGGER_STEP_ID } from '@/workflow/workflow-trigger/constants/TriggerStepId';
-import { isDefined } from 'twenty-ui';
+import { isDefined } from 'twenty-shared';
 
 export const getStepDefinitionOrThrow = ({
   stepId,