feat(ngAnimate): expose a core version of `$animateCss`

A core version of `$animateCss` can now be injected when
ngAnimate is not present. This core version doesn't trigger any
animations in any way. All that it does is apply the provided from
and/or to styles as well as the addClass and removeClass values.

The motivation for this feature is to allow for directives to activate
animations automatically when ngAnimate is included without the need to
use `$animate`.

Closes #12509
Closes #12570