Make sure the schema exists in the alternate DB before creating the table

For SQLite, pretent we have schemas by attaching different database files

Change-Id: I7cfacfd5a52416811d6d8353f837785b469c5e4b
Working version of UR_TEST_FILLDB

It creates a sub that fills in the alternate database, based on rows returned
from the primary DB.  The query plan's loading template is used to figure
out which columns from the result set go in each table.

Change-Id: I285f6fb7fcb0ab697f654177cd56860c2f25ca0c
sqlite now supports a directory of DB files

If the data source's "server" resolves to a directory, it attaches all the
*.sqlite3 files within as schemas.  The primary database (main schema) must
be named 'main.sqlite3' inside the directory

Change-Id: I47b8d064767239ceea26132e91a59bb7e8493124
Extract method for creating the handle for the alternate save DB

We'll want to override it in some subclasses

Change-Id: I16e67fe80685c87dbaf2bdc2e49d10b84d3c851f