Feature description

The Stories experience is being moved to a separate standalone plugin, per #4172. As such, all of the AMP Stories codebase can be removed from the AMP plugin. This includes the experience checkboxes because the AMP plugin would again only be for the website:

Note that this should be done after these issues are resolved: #4200, #4201, #4202. Otherwise, merge conflicts would ensue (though not the end of the world since the merge conflicts would be easy to resolve)

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Acceptance criteria

Implementation brief

QA testing instructions

Demo

Changelog entry