Fix screen resizing after initial launch

[gardenappl]

My program, svitlyna, resizes its screen to fit the image that it's displaying - the resizing happens after the reset vector because the program relies on Console/vector to get the image data.

This emulator has code for handling this scenario but it didn't seem to get triggered for whatever reason, so I re-wrote it slightly, and now it works.

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The other issue is that, for whatever reason, the resizing doesn't always work on Wayland. I tried updating the egui dependency to include this fix, but it didn't seem to work either. However, the new versions require you to specify build features for Wayland and/or X11, and I was able to fix it by adding the x11 feature but not the wayland feature. But I don't think that's a good solution, so I'm not submitting it.

I could try to investigate it further but I am a complete beginner in Rust, in fact these two PRs are my very first lines of Rust code.

[mkeeter]

Thanks, merged (although see #6 for some follow-up cleanups)

I'm a complete beginner with Wayland (and don't have any systems to test on), so am happy to defer updating the egui dependency until someone else wants to drive it 😄