Ready for Release

#1071

A new reactive primitive: `cell`

Overload tracked to work outside of classes Summary This RFC introduces two overloads to the existing tracked function, allowing it to be used outside of classes. Motivation Our documentation / guides currently don't have much of anything on reactivity, and over the years, it's been useful to talk about reactive primitives as things outside of classes, and compose/wrap them in to refactoring boundaries (classes, components, etc). Additionally, other new reactive utilities have an options object that allow power-users to configure equality and dirtying behavior (see: @ember/reactive/collections for those), and we want that same configurability for

#1041

Deprecate target action support.

Deprecate TargetActionSupport Summary Deprecate send and the corresponding TargetActionSupport. Motivation These are legacy patterns that are no longer recommended in modern Ember code. The primary way to interact with this system was the now-deprecated {{action}} modifier/helper. The modern approach is to use standard class methods (optionally decorated with @action) and to pass functions directly, following the Data Down, Actions Up (DDAU) pattern. See also: Target Action Support deprecation guide Detailed design This RFC proposes to deprecate and remove the following: TargetActionSupport mixin, specifically the triggerAction method ActionHandler mixin, specifically the send method ActionSupport mixin, specifically the send method