debugger: Add a couple more keybindings (#31103)

- Add missing handler for `debugger::Continue` so `f5` works
- Add bindings based on VS Code for `debugger::Restart` and
`debug_panel::ToggleFocus`
- Remove breakpoint-related buttons from the debug panel's top strip,
and surface the bindings for `editor::ToggleBreakpoint` in gutter
tooltip instead

Release Notes:

- Debugger Beta: Added keybindings for `debugger::Continue`,
`debugger::Restart`, and `debug_panel::ToggleFocus`.
- Debugger Beta: Removed breakpoint-related buttons from the top of the
debug panel.
- Compatibility note: on Linux, `ctrl-shift-d` is now bound to
`debug_panel::ToggleFocus` by default, instead of
`editor::DuplicateLineDown`.

crates/debugger_ui/src/debugger_ui.rs

@@ -95,6 +95,17 @@ pub fn init(cx: &mut App) {
                         }
                     }
                 })
+                .register_action(|workspace, _: &Continue, _, cx| {
+                    if let Some(debug_panel) = workspace.panel::<DebugPanel>(cx) {
+                        if let Some(active_item) = debug_panel.read_with(cx, |panel, cx| {
+                            panel
+                                .active_session()
+                                .map(|session| session.read(cx).running_state().clone())
+                        }) {
+                            active_item.update(cx, |item, cx| item.continue_thread(cx))
+                        }
+                    }
+                })
                 .register_action(|workspace, _: &StepInto, _, cx| {
                     if let Some(debug_panel) = workspace.panel::<DebugPanel>(cx) {
                         if let Some(active_item) = debug_panel.read_with(cx, |panel, cx| {