Add SVG preview (#32694)

Closes #10454

Implements SVG file preview capability similar to the existing markdown
preview.
- Adds `svg_preview` crate with preview view and live reloading upon
file save.
- Integrates SVG preview button in quick action bar.
- File preview shortcuts (`ctrl/cmd+k v` and `ctrl/cmd+shift+v`) are
extension-aware.

Release Notes:

- Added SVG file preview, accessible via the quick action bar button or
keyboard shortcuts (`ctrl/cmd+k v` and `ctrl/cmd+shift+v`) when editing
SVG files.

crates/zed/src/main.rs

@@ -582,6 +582,7 @@ pub fn main() {
         jj_ui::init(cx);
         feedback::init(cx);
         markdown_preview::init(cx);
+        svg_preview::init(cx);
         welcome::init(cx);
         settings_ui::init(cx);
         extensions_ui::init(cx);