Prevent distribution of classic-editor-remember post meta.

[peterwilsoncc]

Description of the Change

Prevents the distribution of the classic-editor-remember post meta data from one site to another.

This setting is used to determine whether a post should be opened in the block or classic editor on sites with the classic editor plugin installed.

On sites with the plugin installed, the preference should be made by that sites editors. On sites without the plugin installed then the meta data is not needed and fills their post meta table with junk.

Closes #976

How to test the Change

1. Install the classic editor on two Distributor enabled site
2. Set it to allow users to switch between the editor of their choice (Settings > Writing)
3. Author and publish a post in the block editor
4. Open the post in the classic editor
5. Close without saving.
6. Either push or pull the post to another site
7. Edit the Distributed post on the second site
8. Ensure the post still opens in the block editor

Changelog Entry

Fixed - Prevent distribution of classic editor plugin related meta data.

Credits

Props @peterwilsoncc, @faisal-alvi, @jeffpaul

Checklist:

• I agree to follow this project's Code of Conduct.
• I have updated the documentation accordingly.
• I have added tests to cover my change.
• All new and existing tests pass.

[faisal-alvi]

@peterwilsoncc thanks for the work. I've followed the mentioned steps and the distributed post opened in the block editor. Admin/Editor is also able to switch between the editors.