Disable reset to default when custom tab or widget (#19814)

## Context
"Reset to default" action is rejected by the backend for custom entities
because there is no "default" concept for them

## Implementation
Grey out the Reset to default action on record page-layout tabs and
widgets when the entity either has no applicationId yet (unsaved draft —
previously slipped through the existing check), or belongs to the
workspace custom application.

<img width="926" height="370" alt="Screenshot 2026-04-17 at 18 50 31"
src="https://github.com/user-attachments/assets/c7c163f4-17a6-4b69-a66d-90f9085d27a2"
/>

packages/twenty-front/src/modules/page-layout/constants/DefaultWorkflowVersionPageLayout.ts

@@ -39,6 +39,7 @@ export const DEFAULT_WORKFLOW_VERSION_PAGE_LAYOUT: PageLayout = {
       widgets: [
         {
           __typename: 'PageLayoutWidget',
+          applicationId: '',
           id: 'workflow-version-widget-fields',
           isActive: true,
           pageLayoutTabId: 'workflow-version-tab-fields',
@@ -80,6 +81,7 @@ export const DEFAULT_WORKFLOW_VERSION_PAGE_LAYOUT: PageLayout = {
       widgets: [
         {
           __typename: 'PageLayoutWidget',
+          applicationId: '',
           id: 'workflow-version-widget-flow',
           isActive: true,
           pageLayoutTabId: 'workflow-version-tab-flow',