Investigate the feasibility of combining iOS device and simulator builds

We should investigate the feasibility of combining iOS device and simulator support within Qt Creator.

There should be the ability to create a single Kit which handles both hardware and simulator devices. The separate "iOS Device and "iOS Simulator" device types should go away and simply have a single "iOS Device" device type which handles both hardware and simulator devices. The compiler and sysroot can simply refer to the device-specific compiler and sysroot, since they don't have any affect on the compilation itself anyways.

This would fit better with the rest of the devices in Qt Creator (there's no separate Android device vs Android emulator) as well as qmake and Qt itself, since a single build of Qt contains both device and simulator architectures.

Selecting the actual device would then determine whether the build was for hardware or simulator, and this would enable better integration with Xcode (like, generating ONE Xcode project for both simulator and hardware unlike generating two projects like we do now) since it's not really possible to have Xcode projects which support ONLY device or simulator builds.