Allow nested inline templates to be compiled into single file, instead of several

**Is your feature request related to a problem? Please describe.**
In order to power the bicep decompile API, we need to be able to handle nested inline templates when decompiling without requiring the user to handle several files. This is primarily to support two portal integrations:

1. Export resource as Bicep
2. Download template for automation as Bicep

A couple of potential solutions:
* "inline" modules which have already been proposed before (but I can't find the issue...)
* return a zip file instead of a `.bicep` file
* generate a resource of type `microsoft.resources/deployments` instead of generating a module (not a good option)