- remove outer `<div>` in tests,
- use `<ng-container>` instead of `<template>` where possible,
- use *... instead of template (tag or attr) where possible.
Fixes#13816
But use the DOM apis directly.
This also creates a separate `ServerRenderer` implementation
for `platform-server` as it previously reused the `BrowserRenderer`.
BREAKING CHANGE: web worker platform is now exported via separate packages.
Please use @angular/platform-webworker and @angular/platform-webworker-dynamic