Properly calculate y offsets for multi buffer context menus (#15594)

Follow-up of https://github.com/zed-industries/zed/pull/14727

Release Notes:

- Fixed multi buffer context menus not showing properly

Co-authored-by: Max Brunsfeld <max@zed.dev>

crates/editor/src/mouse_context_menu.rs

@@ -10,6 +10,7 @@ use gpui::prelude::FluentBuilder;
 use gpui::{DismissEvent, Pixels, Point, Subscription, View, ViewContext};
 use workspace::OpenInTerminal;
 
+#[derive(Debug)]
 pub enum MenuPosition {
     /// When the editor is scrolled, the context menu stays on the exact
     /// same position on the screen, never disappearing.
@@ -29,6 +30,15 @@ pub struct MouseContextMenu {
     _subscription: Subscription,
 }
 
+impl std::fmt::Debug for MouseContextMenu {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("MouseContextMenu")
+            .field("position", &self.position)
+            .field("context_menu", &self.context_menu)
+            .finish()
+    }
+}
+
 impl MouseContextMenu {
     pub(crate) fn pinned_to_editor(
         editor: &mut Editor,