Select Default GPU to render stream in command line argument.

- [x] I have checked that a similar [feature request](https://github.com/Genymobile/scrcpy/issues?q=is%3Aopen+is%3Aissue+label%3A%22feature+request%22) does not already exist.

**Is your feature request related to a problem? Please describe.**
display window keeps switching gpus to render stream.
i'm unable to pin scrcpy to a single gpu to use, even setting preferred gpu in windows graphics settings does not work.
i run a multi monitor setup, so normally i move the display window to another monitor.

A clear and concise description of what the problem is. Ex. I'm always frustrated when [...]
if i run another gpu resouce intensive app on the same gpu as scrcpy, both suffers.
scrcpy also changes which gpu to render on when moving to different monitors and maximising window.

**Describe the solution you'd like**
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add arguments to the command line on which gpu to use, and it will render the stream using that gpu.

**Describe alternatives you've considered**
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selecting preferred gpu to use in windows graphic settings in windows settings.

**Additional context**
Add any other context or screenshots about the feature request here.
i hope the attached following is helpful.
https://stackoverflow.com/questions/69466240/how-to-specify-particular-gpu-device-to-be-used-at-the-time-of-running-a-program

No source files or tests are named. Start by tracing scrcpy's command-line option handling and desktop rendering initialization, then determine how GPU selection behaves when the window moves between monitors or is maximized. Done means a documented command-line choice keeps rendering on the selected GPU in those cases.

Written by the indexing model from the issue text.