[enhancement]: Change "Aspect" to "Presets and allow customizations

### Is there an existing issue for this?

- [x] I have searched the existing issues

### Contact Details

shanedk on Discord

### What should this feature add?

Implement this idea by Sarp in the Discord: https://discord.com/channels/1020123559063990373/1476859063932555357/1477077529260200118

Rename the dropdown "Aspect" to "Presets" and allow customizations as in Sarp's mockup:

Presets would be named, and would be set to either an aspect ratio (e.g., 2.35:1 or 5:4) or a specific resolution (e.g., 832x1216). For the aspect ratio, the resolution would automatically be set based on the currently-selected model; for the resolution, it would be entered as in the preset, although of course the Optimize button would still be available. When selecting a preset, automatically turn on Lock Aspect Ratio.

Configuration could either be with a user-editable config file or with a panel in Settings; additionally, the Model Manager could also have custom presets for each model, since certain models are optimized for their own unique resolutions.

This idea is ripe, based on previous issues that have been posted and were rejected, while this proposal doesn't seem to have the issues developers were mentioning in those other proposals.

### Alternatives

_No response_

### Additional Content

_No response_