Add Toolbar proxy notice for Atomic sites

[DustyReagan]

Fixes https://github.com/Automattic/dotcom-forge/issues/7622

Proposed changes:

• This PR adds a notice in profile.php for a12ns informing them that the Toolbar is always visible on Atomic sites when connected to the a8c proxy. This is due to the debug-bar-loader plugin forcing the toolbar to be enabled. p1714985574878659-slack-C7YPW6K40
• The message shown below is visible when proxied on Atomic sites.

No proxy & Simple sites	Proxied Atomic sites

Other information:

• Have you written new tests for your changes, if applicable?
• Have you checked the E2E test CI results, and verified that your changes do not break them?
• Have you tested your changes on WordPress.com, if applicable (if so, you'll see a generated comment below with a script to run)?

Jetpack product discussion

No.

Does this pull request change what data or activity we track or use?

Testing instructions:

• Load this PR using the instructions below.
• On your test Atomic site go to /wp-admin/profile.php while connected to the proxy. You should see the notice mentioned above.
• Disconnect from the proxy and refresh the page. The notice should not be visible.
• On a test Classic Simple site, go to /wp-admin/profile.php while connected to the proxy. You should NOT see the notice because Simple sites do not load the debug-bar-loader plugin, so we do not need to show it, as the toolbar works as expected.

[github-actions]

Are you an Automattician? Please test your changes on all WordPress.com environments to help mitigate accidental explosions.

• To test on WoA, go to the Plugins menu on a WordPress.com Simple site. Click on the "Upload" button and follow the upgrade flow to be able to upload, install, and activate the Jetpack Beta plugin. Once the plugin is active, go to Jetpack > Jetpack Beta, select your plugin, and enable the add/profile-toolbar-notice branch.

  • For jetpack-mu-wpcom changes, also add define( 'JETPACK_MU_WPCOM_LOAD_VIA_BETA_PLUGIN', true ); to your wp-config.php file.

• To test on Simple, run the following command on your sandbox:

  bin/jetpack-downloader test jetpack-mu-wpcom-plugin add/profile-toolbar-notice
  

Interested in more tips and information?

• In your local development environment, use the jetpack rsync command to sync your changes to a WoA dev blog.
• Read more about our development workflow here: PCYsg-eg0-p2
• Figure out when your changes will be shipped to customers here: PCYsg-eg5-p2

[github-actions]

Thank you for your PR!

When contributing to Jetpack, we have a few suggestions that can help us test and review your patch:

• ✅ Include a description of your PR changes.
  
• ✅ Add a "[Status]" label (In Progress, Needs Team Review, ...).
  
• ✅ Add testing instructions.
  
• ✅ Specify whether this PR includes any changes to data or privacy.
  
• ✅ Add changelog entries to affected projects
  

This comment will be updated as you work on your PR and make changes. If you think that some of those checks are not needed for your PR, please explain why you think so. Thanks for cooperation 🤖

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[lupus2k]

LGTM!

Not proxied

Proxied