Deprecate "old class binding" syntax

[chancancode]

Basically deprecate and remove this file: https://github.com/emberjs/ember.js/blob/aeef923e9f5f7dde2bc43fcdddabc4a3b98769ec/packages/ember-template-compiler/lib/plugins/transform-old-class-binding-syntax.ts

TL;DR deprecate passing classBindings and classNameBindings as arguments when doing curly component invocations, i.e. instead of {{my-component classNameBindings="foo:bar:baz"}}, write {{my-component class=(if this.foo "bar" "baz")}}, or better yet, <MyComponent class={{if this.foo "bar" "baz"}} />.

Note that classBindings and classNameBindings already does not work on angle bracket invocations.

[chancancode]

The classBindings and classNameBindings feature actually supports a lot of weir micro syntax/features, dashififying the class name etc, so we'll need to dig a bit deeper into the tests to catalog what they are and what the map to, but in each case, there is always a reliable mechanical transformation that you can write instead.

[sandstrom]

If curly components are already on their way out (not officially deprecated, but still), isn't it easier to spend effort elsewhere?

(not against the idea in itself though)

[chancancode]

Curly invocations themselves (which can be used to invoke any component) are not necessarily on their way out, they just have different use cases. Curly invocations support passing positional arguments which makes them a better fit for "helper-like" or "control-flow-like" components (which can be implemented using classic components or a custom component manager).

[chriskrycho]

I believe this was done in #691?

[wagenet]

Looks like this was completed. If not, it should be part of #832