This PR allows to select a device to be used by the Vulkan backend.
Current approach is that it is a command line argument.
`--gpu-device` folowing the index of the device you want to select
**TODO**
- [ ] Provide a list of devices to choose from
- [ ] Selecting a non presenting device has artifacts
- [ ] Add user pref option
- [ ] User decision, should we select device even when it doesn't have
all needed requirements. eg exit on wrong choice.
- [ ] Document the API
