Way to set wgpu adapter and performance preference

### Discussed in https://github.com/orgs/JuliaWGPU/discussions/26

<div type='discussions-op-text'>

<sup>Originally posted by **VarLad** March  7, 2024</sup>
I can't seem to be able to force WGPUgfx to use my iGPU or low power  mode. 
Is there a way to do it? </div>