Allow custom model naming

[mattppal]

Is your feature request related to a problem? Please describe.
Since dbt requires unique model names, our models are named by the convention models/schema/schema__table.sql. When running generate properties, the models are picked up by the wrong names, e.g.

Model locations.locations__county not materialized, did you execute dbt run?. 
Model locations.locations__state not materialized, did you execute dbt run?.

Where the models are actually named

locations.state
locations.county

Describe the solution you'd like
Allow for custom model naming conventions so that model names do not have to equal table names.

[BAntonellini]

Hi @mattppal, thanks for your contribution.

In order for dbt-coves to generate property files properly, model data is obtained from your database through dbt adapter.

This means that both un-materialized and ephemeral models cannot be used.