debugger: Add debug task picker to new session modal (#29702)

## Preview 

![image](https://github.com/user-attachments/assets/203a577f-3b38-4017-9571-de1234415162)


### TODO
- [x] Add scenario picker to new session modal
- [x] Make debugger start action open new session modal instead of task
modal
- [x] Fix `esc` not clearing the cancelling the new session modal while
it's in scenario or attach mode
- [x] Resolve debug scenario's correctly

Release Notes:

- N/A

crates/debugger_ui/src/debugger_ui.rs

@@ -158,6 +158,7 @@ pub fn init(cx: &mut App) {
                                     debug_panel.read(cx).past_debug_definition.clone(),
                                     weak_panel,
                                     weak_workspace,
+                                    None,
                                     window,
                                     cx,
                                 )
@@ -166,14 +167,22 @@ pub fn init(cx: &mut App) {
                     },
                 )
                 .register_action(|workspace: &mut Workspace, _: &Start, window, cx| {
-                    tasks_ui::toggle_modal(
-                        workspace,
-                        None,
-                        task::TaskModal::DebugModal,
-                        window,
-                        cx,
-                    )
-                    .detach();
+                    if let Some(debug_panel) = workspace.panel::<DebugPanel>(cx) {
+                        let weak_panel = debug_panel.downgrade();
+                        let weak_workspace = cx.weak_entity();
+                        let task_store = workspace.project().read(cx).task_store().clone();
+
+                        workspace.toggle_modal(window, cx, |window, cx| {
+                            NewSessionModal::new(
+                                debug_panel.read(cx).past_debug_definition.clone(),
+                                weak_panel,
+                                weak_workspace,
+                                Some(task_store),
+                                window,
+                                cx,
+                            )
+                        });
+                    }
                 });
         })
     })