AdaptorService enhancements

@stuartc , how much of this is already addressed by the latest on `main`?
- [ ] Version matching  
  - What does `latest` _actually_ mean?  
  - Do we have a plan for refreshing/revoking the 'latest'.
- [ ] Make sure the `find_adaptor` functions make sense.
- [ ] Test against `microservice`
- [ ] Module docs  
  - Make sure the suffix `{adaptors_path}/node_modules` is explained.