Release `generator` and `autorest.bicep` as public npm packages

**Is your feature request related to a problem? Please describe.**
To generate Bicep Extensibility Provider Types, I am required to keep a copy of the `generator` and `autorest.bicep` code see here for example:
* https://github.com/Azure/bicep-types-k8s/tree/main/src/generator
* https://github.com/Azure/bicep-types-az/tree/main/src/generator
* https://github.com/Azure/bicep-types-k8s/tree/main/src/autorest.bicep
* https://github.com/Azure/bicep-types-az/tree/main/src/autorest.bicep

This presents several problems:

* If the type definition format changes, I am required to update and reconcile conflicts on the generator code
* Keeping the different copies synchronized is unwieldy

**Describe the solution you'd like**

Publish `generator` and `autorest.bicep` as versioned npm packages thus removing the need for keeping copies of the code

Review the generator and autorest.bicep copies linked under bicep-types-k8s and bicep-types-az to understand their package boundaries and synchronization needs. Define versioned public npm packages for both components so downstream projects no longer need to keep local copies; completion means consumers can depend on the published packages.

Written by the indexing model from the issue text.