Support building configuration documents with filtered logical schemas

[jng]

When overriding the schema for an ODBC feature source, it needs to do a full schema walk to construct the logical schema component of the configuration document. For really large datastores, this will cause a long wait (or timeout).

We can avoid doing a schema walk by prompting the user to select the Feature Classes to include in the configuration document. This has 2 benefits:

• We only request a partial schema and can tap into FDO RFC23 enhancements where applicable
• The feature source only exposes a partial view of the entire datastore, reducing the attack surface.

Current focus will be for the ODBC editor, but can be extended to any other Feature Source editor that supports configuration and FDO RFC23 APIs

[jng]

Fixed r6747