[FRONT COMPONENTS] Headless components (#18096)

## Description

- Add `isHeadless` field to `FrontComponent` entity so front components
can run without rendering UI in the command menu
- Introduce headless front component mounting logic:
`HeadlessFrontComponentMountRoot` at the application root,
`useMountHeadlessFrontComponent`, and `useUnmountHeadlessFrontComponent`
hooks to mount/unmount headless components
- Expand the SDK with new action components (`Action`, `ActionLink`,
`ActionOpenSidePanelPage`) and host communication functions
(`openSidePanelPage`, `unmountFrontComponent`)
- Move `CommandMenuPages` type to twenty-shared so the SDK can reference
it for side panel navigation

## Video QA



https://github.com/user-attachments/assets/4f9e3bb1-fcd1-42be-b3f4-a97e80c2add2

packages/twenty-front/src/modules/command-menu/hooks/useOpenFrontComponentInCommandMenu.ts

@@ -1,7 +1,7 @@
 import { useCommandMenu } from '@/command-menu/hooks/useCommandMenu';
 import { viewableFrontComponentIdComponentState } from '@/command-menu/pages/front-component/states/viewableFrontComponentIdComponentState';
-import { CommandMenuPages } from '@/command-menu/types/CommandMenuPages';
 import { useRecoilCallback } from 'recoil';
+import { CommandMenuPages } from 'twenty-shared/types';
 import { type IconComponent } from 'twenty-ui/display';
 import { v4 } from 'uuid';