Add image dimension and file size information (#21675)

Closes https://github.com/zed-industries/zed/issues/21281

@jansol, kindly take a look when you're free.


![image](https://github.com/user-attachments/assets/da9a54fa-6284-4012-a243-7e355a5290d3)

Release Notes:

- Added dimensions and file size information for images.

---------

Co-authored-by: tims <0xtimsb@gmail.com>
Co-authored-by: Marshall Bowers <git@maxdeviant.com>

crates/image_viewer/src/image_viewer_settings.rs

@@ -0,0 +1,42 @@
+use gpui::App;
+use schemars::JsonSchema;
+use serde::{Deserialize, Serialize};
+use settings::{Settings, SettingsSources};
+
+/// The settings for the image viewer.
+#[derive(Clone, Debug, Serialize, Deserialize, JsonSchema, Default)]
+pub struct ImageViewerSettings {
+    /// The unit to use for displaying image file sizes.
+    ///
+    /// Default: "binary"
+    #[serde(default)]
+    pub unit: ImageFileSizeUnit,
+}
+
+#[derive(Clone, Copy, Debug, Serialize, Deserialize, JsonSchema, Default)]
+#[serde(rename_all = "snake_case")]
+pub enum ImageFileSizeUnit {
+    /// Displays file size in binary units (e.g., KiB, MiB).
+    #[default]
+    Binary,
+    /// Displays file size in decimal units (e.g., KB, MB).
+    Decimal,
+}
+
+impl Settings for ImageViewerSettings {
+    const KEY: Option<&'static str> = Some("image_viewer");
+
+    type FileContent = Self;
+
+    fn load(
+        sources: SettingsSources<Self::FileContent>,
+        _: &mut App,
+    ) -> Result<Self, anyhow::Error> {
+        SettingsSources::<Self::FileContent>::json_merge_with(
+            [sources.default]
+                .into_iter()
+                .chain(sources.user)
+                .chain(sources.server),
+        )
+    }
+}