This change renames the previous module api implementation
to singleton types.

When a singleton type is registered, a type name must be provided
that is used when accessing the API from QML. This makes the
implementation more consistent with the rest of QML.

Task-number: QTBUG-26549
Change-Id: Iab0bb1ccf516bd3ae20aee562a64d22976e0aecd
Reviewed-by: Chris Adams <christopher.adams@nokia.com>