Spin-off from #1499596-96: Introduce a basic entity form controller:

I've not touched the new entity.module helpers much, in particular the $operation related handling. I'm no fan of the $operation term, while I think introducing the concept makes sense. It's the analogy the view-modes for entity-forms and if field API would support it, it would help a lot to ease customizing registration forms or configuring different form-widgets for searching? I think this needs some more though and probably a rename as it doesn't map to operation (that would be e.g 'delete', 'create'?). Anyway, given that this blocks some further important work I guess we can care about that in a follow-up.

To be completed.


Issue tags:+Field system

It sounds like the suggested $operation maps 1:1 to the "Manage Fields" Field UI pages?

Ah-ha! I just see and realize that we only have view modes on "Manage Display", but no equivalent on "Manage Fields" :)

I'm pretty sure that I've seen an issue for that in the past already... but can't find it right now.

Updating tags.

We have EntityFormMode & EntityViewMode config entities and manage screens for both
So should they auto-created to map 1:1 to operations?