Add ability to use Quick Edit to the latest_revision route

Problem/Motivation

At the moment, Content Moderation and Quick Edit are incompatible. Quick edit is not integrated into revisions of entities that are the latest revision.

For example, enable moderation on an entity bundle, publish a draft, then create a new draft of that entity, visit the latest version tab witness the lack of quickedit options.

You can view a screencast showcasing the current problems here: https://www.youtube.com/watch?v=gvnXaT7HCeU

Proposed resolution

There are a number of steps that need to happen to make these modules work together:

1. Load the latest revision of an entity for routes that deliver quickedit form components.
2. Ensure that Contextual Links display on the latest revision of a Node. Otherwise Quick Edit will be inaccessible to users.

Latest patch in action:

Remaining tasks

Review the provided patch.

1. (I think the existing permissions already cover this?)

User interface changes

Additional edit and quick edit contextual links rendered on the latest version of an entity.

API changes

An additional contextual link "group" exclusively for the latest version of an entity.

Data model changes

None.