Clarify storybook tests (#6073)

In this PR, I'm simplifying storybook setup:
1) Remove build --test configuration that prevent autodocs. We are not
using autodocs at all (the dev experience is not good enough), so I have
completely disabled it.
2) Clarify `serve` vs `test` vs `serve-and-test` configurations


After this PR:
- you can serve storybook in two modes: `npx nx run
twenty-front:storybook:serve:dev` and `npx nx run
twenty-front:storybook:serve:static`
- you can run tests agains an already served storybook (this is useful
in dev so you don't have to rebuild everytime to run tests): `npx nx run
twenty-front:storybook:test`
- you can conbine both: `npx nx run
twenty-front:storybook:serve-and-test:static`

packages/twenty-front/.storybook/main.ts

@@ -45,17 +45,5 @@ const config: StorybookConfig = {
     name: '@storybook/react-vite',
     options: {},
   },
-  build: {
-    test: {
-      disableMDXEntries: true,
-      disabledAddons: [
-        '@storybook/addon-docs',
-        '@storybook/addon-essentials/docs',
-      ],
-    },
-  },
-  docs: {
-    autodocs: false,
-  },
 };
 export default config;