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/zed.rs

@@ -4323,6 +4323,7 @@ mod tests {
                 "search",
                 "snippets",
                 "supermaven",
+                "svg",
                 "tab_switcher",
                 "task",
                 "terminal",