Editor Full Screen Modification is tied to Shared Blocks Module

On a client project, we'd like to have the code that turns off the full-screen editor experience from this module run for us, but the code only runs if the `shared-blocks` module is active on a site. We have it turned off, and therefore lose access to the fullscreen fix. I propose that the two functionalities shouldn't depend on each other and the fullscreen fix should be default for all installations or have its own config setting.

Steps to reproduce:
1. Disable the CMS `shared-blocks` module via config
1. Load up the editor screen and observe that the fullscreen view takes over, and the Altis code to turn it off never runs.

This is because the JS code that works with the editor only runs if the `shared-blocks` module is active.

Ref:

https://github.com/humanmade/altis-cms/blob/1d07bbfe2e3ca3be36eb31c544bbbb758fbc293a/inc/namespace.php#L43-L45

https://github.com/humanmade/altis-cms/blob/1d07bbfe2e3ca3be36eb31c544bbbb758fbc293a/inc/block_editor/namespace.php#L144-L164

Acceptance criteria:

- [ ] The fullscreen editor fix runs whether the `shared-blocks` module is active or not.