No error set on PositionSource when couldn't fetch location

[Didier Roche-Tolomelli]

PositionSource, when used on the phone (OTA5), didn't set the right sourceError on its object.
run the snippet below, deny location permission on that application

1. see that onPositionChanged event is fired, with "QGeoCoordinate(nan, nan,nan)" for positionSource.position.coordinate. However, if you read the documentation:
"However, whenever a positionChanged signal has been received, at least position::coordinate::latitude, position::coordinate::longitude, and position::timestamp can be assumed to be valid."

So, this forces the developer to add an extra positionSource.position.coordinate.isValid check. The event shouldn't be fired to respect the documentation

2. sourceError is always PositionSource.NoError (as if the location was permitted). It should rather be, from the documentation PositionSource.AccessError.

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snippet:

import QtPositioning 5.2
import QtLocation 5.3

PositionSource {
    id: pos
    active: true
    updateInterval: 120000 // 2 mins
    onPositionChanged: {
        console.log("error value: " + pos.sourceError)
        console.log("coordinates " + positionSource.position.coordinate);
    }
}