Image viewer (#9425)

This builds on #9353 by adding an image viewer to Zed. Closes #5251.

Release Notes:

- Added support for rendering image files
([#5251](https://github.com/zed-industries/zed/issues/5251)).

<img width="1840" alt="image"
src="https://github.com/zed-industries/zed/assets/836375/3bccfa8e-aa5c-421f-9dfa-671caa274c3c">

---------

Co-authored-by: Mikayla Maki <mikayla@zed.dev>

crates/workspace/src/pane.rs

@@ -172,7 +172,7 @@ pub struct Pane {
     new_item_menu: Option<View<ContextMenu>>,
     split_item_menu: Option<View<ContextMenu>>,
     //     tab_context_menu: View<ContextMenu>,
-    workspace: WeakView<Workspace>,
+    pub(crate) workspace: WeakView<Workspace>,
     project: Model<Project>,
     drag_split_direction: Option<SplitDirection>,
     can_drop_predicate: Option<Arc<dyn Fn(&dyn Any, &mut WindowContext) -> bool>>,