The View Transitions API enables easy animations when transitioning between different DOM states. This commit adds an opt-in feature to the Router which runs the component activation and deactivation logic in the document.startViewTransition callback. If the browser does not support this API, route activation and deactivation will happen synchronously.

resolves #49401

PR Close #51314

`typings` is not valid for TypeScript. See: https://www.typescriptlang.org/docs/handbook/esm-node.html for more information.

PR Close #51737

`jest-preset-angular` imports `zone.js` using deep imports. This commit temporary allow this until the correct entry-points are used upstream.

See: thymikee/jest-preset-angular#2162

PR Close #51737

Previously effects were queued as they became dirty, and this queue was
flushed at various checkpoints during the change detection cycle. The result
was that change detection _was_ the effect runner, and without executing CD,
effects would not execute. This leads a particular tradeoff:

* effects are subject to unidirectional data flow (bad for dx)
* effects don't cause a new round of CD (good/bad depending on use case)
* effects can be used to implement control flow efficiently (desirable)

This commit changes the scheduling mechanism. Effects are now scheduled via
the microtask queue. This changes the tradeoffs:

* effects are no longer limited by unidirectional data flow (easy dx)
* effects registered in the Angular zone will trigger CD after they run
  (same as `Promise.resolve` really)
* the public `effect()` type of effect probably isn't a good building block
  for our built-in control flow, and we'll need a new internal abstraction.

As `effect()` is in developer preview, changing the execution timing is not
considered breaking even though it may impact current users.

PR Close #51049

PR Close #51742