The Windows Bluetooth stack uses private IOCTLs in order to set the [discoverability](https://learn.microsoft.com/en-us/windows/win32/api/bluetoothapis/nf-bluetoo...) and [connectability](https://learn.microsoft.com/en-us/windows/win32/api/bluetoothapis/nf-bluetoo...) status of a local radio. This MR introduces the wine-specific IOCTL `IOCTL_WINBTH_RADIO_SET_FLAG` for the same purpose, as most applications seem to the Win32 API itself for these operations. -- v14: bluetoothapis: Implement BluetoothEnableDiscovery. bluetoothapis/tests: Add tests for BluetoothEnableDiscovery. bluetoothapis: Add stub for BluetoothEnableDiscovery. bluetoothapis: Implement BluetoothEnableIncomingConnections. bluetoothapis/tests: Add tests for BluetoothEnableIncomingConnections. bluetoothapis: Add stub for BluetoothEnableIncomingConnections. winebth.sys: Call bluez_watcher_close as part of bluetooth_shutdown. winebth.sys: Implement IOCTL_WINEBTH_RADIO_SET_FLAG. https://gitlab.winehq.org/wine/wine/-/merge_requests/7216