Explore support for tokens referencing external RIBs in templates

**Use case**
Generated templates for coordination / builder shell that work with other RIBs.

**Idea**
- Template file referencing another RIB with token
- gradle config sets token
- plugin asks for external RIB name to be replaced into token

Start by locating the template file, Gradle configuration, and plugin entry point described in the issue. Determine how an external RIB name would be supplied and replaced in generated coordination or builder-shell templates; done means the intended external-RIB reference works end to end.

Written by the indexing model from the issue text.