Use the Windshaft query-rewriter interface to adapt queries so
they use available overview tables.
This requires a version of Windshaft that implements the query-rewriter
interface (package.json/npm-shrinkwap.json have yet to be updated)
Now data for multiple tables is obtained in one call, simplifying the
use of this function. Also base table is returned as an oid, so we
now have the overview base table names with schema only when needed.
Make beforeLayergroupCreate to return a datasource with different
authentication for the different layers.
- Named layers will get access to private tables in case it's needed
Changes in MapConfigNamedLayersAdapter:
- It will retrieve the dbAuth params only if named layers are present so
there is no extra overhead for normal layers
- Rename queue function signature from `callback` to `done` so it is easier
to follow the code
Add several tests to validate `named` layers authentication
