Support separate paragraph item editing with contextual links

Problem/Motivation

Paragraphs are now only editable in the host entity edit page.

Proposed resolution

It would be nice if users can decide in the field widget settings if contextual links for each paragraph item are available, making the items editable per paragraph item entity.

The default way would stay the same, but people who'd like to offer their users direct editing links, will be able to do so.

(Note: I mailed about this with the jeroen-b (module-author) who suggested the field widget settings option)

Remaining tasks

The current latest patch includes functionality that has since been split off into #2715833: Delete/insert paragraphs with contextual links → , which added complexity beyond this ticket's original scope. So a new patch needs to be produced without that, that should also cover the following concerns which I don't think it addressed anyway:

• Other revisionable entity types (e.g. beans) should probably be handled, rather than being specific to nodes. We could have some more entity-type-generic code that handles that. (james.williams, comment 34)
• As per ✨ Entity translation support for Drupal 7 Needs work , depending on how language is handled, we'll have to correctly set the paragraph field values, rather than being hardcoded to 'Language neutral'. (mihai_brb, comment 33)