Cannot render macros from content rest API

The problem: If you request the content body using the content rest API, and the content contains macros, the macros don't work (in most cases).

The cause:
1 - Some macros don't explicitly list their web resource dependencies, and so the web resource is not included in the response from the API.
2 - Web resources that are included in the superbatch are excluded from API response, so if the super batch doesn't exist on the page, then javascript errors are thrown due to missing dependencies.
3 - Some macros assume a page load lifecycle that will have a load/ready event. When using the rest API this is often not the case.