perf(*): don't trigger digests after enter/leave of structural directives

ngIf, ngInclude, ngSwitch, and ngView now use the `done` callback functions on animation runners returned
by leave/enter animations to do internal cleanup (and $anchorScroll for ngInclude and ngView).
Previously, they were using promise callbacks (`then`), which caused an unnessecary digest.

Background:

In https://github.com/angular/angular.js/commit/bf0f5502b1bbfddc5cdd2f138efd9188b8c652a9, animation
promises where introduced instead of animation callbacks. These promises were however not tied to
the digest cycle, so you had to manually call `$apply` inside them.

This was changed in https://github.com/angular/angular.js/commit/c8700f04fb6fb5dc21ac24de8665c0476d6db5ef,
so animation promise callbacks would always trigger a `$digest`. This meant that several built-in
directives would now trigger additional digests on leave (ngIf, ngSwitch) or enter/leave (ngInclude,
ngView). The `done` callback, which receives a single argument indicating success / failure was
introduced to allow digest-less responses, but wasn't applied to these directives.

Note that this applies to all calls to $animate.enter/leave, even if ngAnimate isn't included, and
no actual animations are running, because the animation runner code is in the core ng module.

Fixes #15322
Closes #15345