UI: Fix notifications not appearing in new layout

[JReinhold]

What I did

This PR adds the Notifications component back into the manager's layout, that was removed by accident at some point during the development.

This is not done, here are screenshots of how it looks:

Desktop

It's unfortunate (and completely coincidental) that the default notification with the default sidebar size aligns this way, I think we should move/resize one of them.

Mobile

Should we move the notification up, or remove it completely on mobile?

The settings pages that the What's New notification takes you to is not accessible by normal means on mobile. And it's actually broken right now, the iframe containing the blogpost having a 0 px height.

Checklist for Contributors

Testing

The changes in this PR are covered in the following automated tests:

• stories
• unit tests
• integration tests
• end-to-end tests

Manual testing

This section is mandatory for all contributions. If you believe no manual test is necessary, please state so explicitly. Thanks!

Documentation

• Add or update documentation reflecting your changes
• If you are deprecating/removing a feature, make sure to update
  MIGRATION.MD

Checklist for Maintainers

• When this PR is ready for testing, make sure to add ci:normal, ci:merged or ci:daily GH label to it to run a specific set of sandboxes. The particular set of sandboxes can be found in code/lib/cli/src/sandbox-templates.ts

• Make sure this PR contains one of the labels below:

  Available labels

  • bug: Internal changes that fixes incorrect behavior.
  • maintenance: User-facing maintenance tasks.
  • dependencies: Upgrading (sometimes downgrading) dependencies.
  • build: Internal-facing build tooling & test updates. Will not show up in release changelog.
  • cleanup: Minor cleanup style change. Will not show up in release changelog.
  • documentation: Documentation only changes. Will not show up in release changelog.
  • feature request: Introducing a new feature.
  • BREAKING CHANGE: Changes that break compatibility in some way with current major version.
  • other: Changes that don't fit in the above categories.

🦋 Canary release

This pull request has been released as version 0.0.0-pr-24281-sha-534a6350. Install it by pinning all your Storybook dependencies to that version.

More information

Published version	0.0.0-pr-24281-sha-534a6350
Triggered by	@cdedreuille
Repository	storybookjs/storybook
Branch	fix-notifications-in-new-layout
Commit	534a6350
Datetime	Tue Sep 26 13:11:12 UTC 2023 (1695733872)
Workflow run	6313164220

To request a new release of this pull request, mention the @storybookjs/core team.

core team members can create a new canary release here or locally with gh workflow run --repo storybookjs/storybook canary-release-pr.yml --field pr=24281