No option for nearest neighbor when upscaling from N64 resolution

[coavins]

• Go to Settings > Graphics
• Enable advanced settings
• Enable "Set fixed vertical resolution"
• Select "Native N64 (240p)"
• Observe a big difference between the "Viewport dimensions" and "Internal resolution" sizes.
• Return to the game and see that it's blurry.

There is no option to change the upscaling filter to use nearest neighbor.

[coavins]

See proof of concept commits:
coavins/libultraship@d73a742
coavins@3a2e7f7

[coavins]

See above PRs which resolve this issue