Change pending state of js breakpoints if they're hit

Breakpoints in js parts of qml stay in the 'pending' state (displayed by an hour glass) even while debugging.

The core of the problem is that the JS debugger does not check whether breakpoints can be set or not ... we know that a breakpoint is valid only when hitting it. So the minimal change would be to move it from the pending to the non-pending state, as soon as it is hit.