Separate source and destination of tables

[maciejgrzybek]

There should be a way to define different table name (and schema) to be created in DB than the one specified in repository.
E.g. this should be possible to instantiate tpcds.customer in DB under schema foo and name bar.
Example of syntax:

tables: tpcds.customer -> public.tpcds_customer, tpch.customer -> public.tpch_customer

would create two tables: tpch_customer and tpcds_customer, both in schema public based on tables registered in TableRegistry as tpch.customer and tpcds.customer respectively.

This would simplify table names resolution and make it less confusing. What's possible now: referring to fully qualified table name, e.g. public.nation can return nation (schemaless).

When this is implemented, we could enforce fully qualified names as source tables. This would make test definitions more explicit.

CC: @kokosing