Setup the foundation for Twenty UI library. (#4423)

* feat: create a separate package for twenty-ui, extract the pill component with hard-coded theme values into it, and use the component inside twenty-front to complete the setup

* feat: extract the light and the dark theme into twenty-ui and update the AppThemeProvider component inside twenty-front to consume themes from twenty-ui

* fix: create a decorator inside preview.tsx to provide a default theme to storybook development server

* fix: remove redundant type declarations and revert back the naming convention for theme declarations

* fix: introduce a default value for pill label within the story for development server

* fix: introduce the nx script into package.json for twenty-ui and resolve imports for theme type within the package

* fix: remove the pill component from the twenty-front package along with the story for it

* fix: revert the package versions to those before running the nx cli command for storybook init

* feat: update readme to include details for building the ui library and starting the storybook development server

* fix: include details about twenty-ui inside jest.config for twenty-front to complete front-jest job

* - Added preview head for font
- Added theme addon for light/dark switch
- Added ComponentDecorator

---------

Co-authored-by: Lucas Bordeau <bordeau.lucas@gmail.com>

packages/twenty-ui/src/testing/decorators/ComponentDecorator.tsx

@@ -0,0 +1,13 @@
+import { Decorator } from '@storybook/react';
+
+import { ComponentStorybookLayout } from '../ComponentStorybookLayout';
+
+export const ComponentDecorator: Decorator = (Story, context) => {
+  const { container } = context.parameters;
+
+  return (
+    <ComponentStorybookLayout width={container?.width}>
+      <Story />
+    </ComponentStorybookLayout>
+  );
+};