PUBLIC_BROWSE_GROUP scans are not always supported. In such cases
more targeted service scans are to be used. This patch modifies
QBluetoothServiceDiscoveryAgent such that when a uuid filter
is set targeted service scans are used rather than generic
PUBLIC_BROWSE_GROUP ones.

QBluetoothSocket always scans with an applied uuid filter and
therefore directly benefits from the patch.

Change-Id: I94997d2cf8f70fa7db5422d78c8bfdbe2aa1dbbc
Task-number: QTBUG-53041
Reviewed-by: Timur Pocheptsov <timur.pocheptsov@theqtcompany.com>