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.

assets/keymaps/default-linux.json

@@ -491,13 +491,27 @@
       "ctrl-k r": "editor::RevealInFileManager",
       "ctrl-k p": "editor::CopyPath",
       "ctrl-\\": "pane::SplitRight",
-      "ctrl-k v": "markdown::OpenPreviewToTheSide",
-      "ctrl-shift-v": "markdown::OpenPreview",
       "ctrl-alt-shift-c": "editor::DisplayCursorNames",
       "alt-.": "editor::GoToHunk",
       "alt-,": "editor::GoToPreviousHunk"
     }
   },
+  {
+    "context": "Editor && extension == md",
+    "use_key_equivalents": true,
+    "bindings": {
+      "ctrl-k v": "markdown::OpenPreviewToTheSide",
+      "ctrl-shift-v": "markdown::OpenPreview"
+    }
+  },
+  {
+    "context": "Editor && extension == svg",
+    "use_key_equivalents": true,
+    "bindings": {
+      "ctrl-k v": "svg::OpenPreviewToTheSide",
+      "ctrl-shift-v": "svg::OpenPreview"
+    }
+  },
   {
     "context": "Editor && mode == full",
     "bindings": {

assets/keymaps/default-macos.json

@@ -545,11 +545,25 @@
       "cmd-k r": "editor::RevealInFileManager",
       "cmd-k p": "editor::CopyPath",
       "cmd-\\": "pane::SplitRight",
-      "cmd-k v": "markdown::OpenPreviewToTheSide",
-      "cmd-shift-v": "markdown::OpenPreview",
       "ctrl-cmd-c": "editor::DisplayCursorNames"
     }
   },
+  {
+    "context": "Editor && extension == md",
+    "use_key_equivalents": true,
+    "bindings": {
+      "cmd-k v": "markdown::OpenPreviewToTheSide",
+      "cmd-shift-v": "markdown::OpenPreview"
+    }
+  },
+  {
+    "context": "Editor && extension == svg",
+    "use_key_equivalents": true,
+    "bindings": {
+      "cmd-k v": "svg::OpenPreviewToTheSide",
+      "cmd-shift-v": "svg::OpenPreview"
+    }
+  },
   {
     "context": "Editor && mode == full",
     "use_key_equivalents": true,