The basic `FindAllAsync()` method returns a collection of `DeviceInformation` objects representing all device interfaces on the system. This MR adds a basic implementation of this method, and the associated `IDeviceInformation` and `DeviceInformationCollection` objects it returns. For `IDeviceInformation`, this MR only implements the `Id()` method, which returns the symbolic link for the registered interface.
-- v4: windows.devices.enumeration: Implement IIterable<IDeviceInformation *> for DeviceInformationCollection. windows.devices.enumeration: Implement IndexOf() and GetMany() for DeviceInformationCollection. windows.devices.enumeration: Create IDeviceInformation objects from all present device interfaces. windows.devices.enumeration: Add a stubbed IDeviceInformation implementation for device interfaces. windows.devices.enumeration: Add a stubbed implementation for FindAllAsync() and DeviceInformationCollection. windows.devices.enumeration/tests: Add conformance tests for IIterable and IIterator interfaces in DeviceInformationCollection. windows.devices.enumeration/tests: Add conformance tests for GetMany() and IndexOf() methods in DeviceInformationCollection. windows.devices.enumeration/tests: Add conformance tests for FindAllAsync().