This PR adds support for configuring both a light and dark icon theme in
`settings.json`.
In addition to accepting just an icon theme name, the `icon_theme` field
now also accepts an object in the following form:
```jsonc
{
"icon_theme": {
"mode": "system",
"light": "Zed (Default)",
"dark": "Zed (Default)"
}
}
```
Both `light` and `dark` are required, and indicate which icon theme
should be used when the system is in light mode and dark mode,
respectively.
The `mode` field is optional and indicates which icon theme should be
used:
- `"system"` - Use the icon theme that corresponds to the system's
appearance.
- `"light"` - Use the icon theme indicated by the `light` field.
- `"dark"` - Use the icon theme indicated by the `dark` field.
Closes https://github.com/zed-industries/zed/issues/24695.
Release Notes:
- Added support for configuring both a light and dark icon theme and
switching between them based on system preference.
cc931a8fcc