Improve order by/selection logic for database layer.
This was extracted from the postponed !311.
The order by stuff previously only allowed specifying a particular field. We should also be able to sort based on arbitrary expressions, and such expressions will require the ability to bind arguments using the "?" syntax. This change provides a Java abstraction for the order by, and improves the handling of selection arguments that need to bind to "?" so that both the selection (i.e. `WHERE` clause) and the `ORDER BY` clause can provide arguments as required.
See merge request !329
e285fd6f38