Microfrontend support

# 🚀 Feature request
Webpack 5 Module Federation API will be a game changer to the web.
So bringing support to Angular CLI once Webpack 5 is released and supported will also be a game changer to Angular projects using the CLI.

### Command (mark with an `x`)

- [ ] new
- [ ] build
- [ ] serve
- [ ] test
- [ ] e2e
- [ ] generate
- [ ] add
- [ ] update
- [ ] lint
- [ ] xi18n
- [ ] run
- [ ] config
- [ ] help
- [ ] version
- [ ] doc

### Description
Once Angular CLI support Webpack 5 #17555 it is important to also support its new API called Module Federation that allow sharing modules in runtime among applications.

### Describe the solution you'd like
Support Webpack 5 Module Federation.

### Describe alternatives you've considered
No alternative considered.

Start by reading Angular CLI issue #17555 and the CLI's build and serve entry points, then review the Webpack 5 Module Federation API requirements. Done means defining and implementing Angular CLI support for sharing modules at runtime among applications, with the relevant CLI behavior covered by tests.

索引モデルが issue の本文から書いたものです。