QModelIndex: clean up integer size confusion in the API

QModelIndex: clean up integer size confusion in the API

QAIM::createIndex() took either int or quint32, but QMI::internalId()
returned qint64.

In the new interface, createIndex() takes, and internalId() provides,
integers of type quintptr.

This matches the storage size of the void* in the model index and
avoids truncation.

Remove the
  createIndex(int, int, quint32) and
  \obsolete createIndex(int,int,int)
overloads.

This makes a literal 0 in the third parameter ambiguous now.
The solutions have been noted in changes-5.0.0.

Change-Id: I0a0ecd8430eaf695129a4d09d14d4e30745485c4
Reviewed-by: Stephen Kelly <stephen.kelly@kdab.com>