debugger: Add memory view (#33955)

This is mostly setting up the UI for now; I expect it to be the biggest
chunk of work.

Release Notes:

- debugger: Added memory view

---------

Co-authored-by: Anthony Eid <hello@anthonyeid.me>
Co-authored-by: Mikayla Maki <mikayla.c.maki@gmail.com>
Co-authored-by: Mikayla Maki <mikayla@zed.dev>

crates/ui/src/components/context_menu.rs

@@ -668,7 +668,7 @@ impl ContextMenu {
         }
     }
 
-    fn select_next(&mut self, _: &SelectNext, window: &mut Window, cx: &mut Context<Self>) {
+    pub fn select_next(&mut self, _: &SelectNext, window: &mut Window, cx: &mut Context<Self>) {
         if let Some(ix) = self.selected_index {
             let next_index = ix + 1;
             if self.items.len() <= next_index {