Make sort order with unset field act on a detail presence

...so that the organizer item with a detail of the specified type
would appear before or after the organizer item that lacks a detail
of the specified type, according to sortorder's blankPolicy().

Change-Id: I9ca28dc03dc5d6d4a28475ee91509fd0d5eee2ac
Reviewed-by: Christopher Adams <chris.adams@jollamobile.com>
Make simple wrappers don't derive from QQmlParserStatus

This completes 3275aad72a85f6f7e32f80c67c1e6fd87d8ab68c
and fixes similar issues not handled by it.

Change-Id: I07e7ec866864887866a72b92e453e83d9bb681f6
Reviewed-by: Matthew Vogt <matthew.vogt@qinetic.com.au>
Reviewed-by: Christopher Adams <chris.adams@jollamobile.com>
Reviewed-by: Robin Burchell <robin+qt@viroteck.net>