Migrate all instances of code-editor to code-demo to allow the users to see the result

[NothingEverHappens]

Lots of pages right now only include the code and not the demos. e.g.

The goal is to use code-demo component which actually displays the result

[kirjs]

Here are couple examples: https://github.com/codelab-fun/codelab/commit/8994a4a61a756ad7cf22b87f77d6b9f3020cb37e https://github.com/codelab-fun/codelab/commit/2f45f8a5827e9f85b050a6391ba0a7b5347a92ab

[kirjs]

Here are some examples where this can work: http://localhost:4200/angular/templates/data-binding-extras http://localhost:4200/angular/templates/event-binding

[kirjs]

http://localhost:4200/angular/component-tree/module