Ui for Comment entity

Problem/Motivation

Following the modification of the module architecture comments are now compatible and can be used directly with Form Mode Manager. Only the editing actions are visible out of the box via the "comment / 1 / edit" pages on the horizontal tabs or directly on the canonical "comment / 1 / edit / xxxxx" link. However, the way in which this entity is used poses a lot of problem specific to each use case and we must think about a simple but flexible UI to allow the management of form modes on the comments.

Proposed resolution

In serious tracks it would be convenient to implement a formatter that extends "CommentDefaultFormatter" and allows the user to choose via FormDisplay which form mode will be used by the service "comment.lazy_builders: renderForm" responsible for the form display . This at first would allow users to create comment fields and to display a more or less rich form. It would pose in a second time a problem with the level of the permissions and the rights or the possibility of implementing fallbacks to have a form form which is enriched according to the rights of each one. This is part of another add-on to Form Mode Manager because it is very specific.

This last question also poses for the formatter that implements the lazy. The support being provided by Form Mode Manager devriont we add the formatter in a module separate or under module to separate the concepts and let Form Mode Manager take care of the generic part then children who relies on the API to format the more specific part.