Remove Type from config.Reference struct

[muvaf]

What problem are you facing?

We now have TerraformName to represent the corresponding resource, hence Type is unnecessary and could be derived from map[string]*config.Resource map.

How could Terrajet help solve your problem?

Make the existing map[string]*config.Resource map available to CRD builder so that it can look up the type name and write to file, hence remove the only usage of the Type field.