Improve the debugger shortcut UX

- Display the shortcut in the button tooltips by defining the shortcut
  on the buttons as well.
- Swap "Step Over" and "Step Into" in the Debug menu to match the button
  order in the Debugger bottom panel.

editor/plugins/script_editor_plugin.cpp

@@ -3308,8 +3308,8 @@ ScriptEditor::ScriptEditor(EditorNode *p_editor) {
 	debug_menu->set_text(TTR("Debug"));
 	debug_menu->set_switch_on_hover(true);
 	debug_menu->get_popup()->set_hide_on_window_lose_focus(true);
-	debug_menu->get_popup()->add_shortcut(ED_SHORTCUT("debugger/step_over", TTR("Step Over"), KEY_F10), DEBUG_NEXT);
 	debug_menu->get_popup()->add_shortcut(ED_SHORTCUT("debugger/step_into", TTR("Step Into"), KEY_F11), DEBUG_STEP);
+	debug_menu->get_popup()->add_shortcut(ED_SHORTCUT("debugger/step_over", TTR("Step Over"), KEY_F10), DEBUG_NEXT);
 	debug_menu->get_popup()->add_separator();
 	debug_menu->get_popup()->add_shortcut(ED_SHORTCUT("debugger/break", TTR("Break")), DEBUG_BREAK);
 	debug_menu->get_popup()->add_shortcut(ED_SHORTCUT("debugger/continue", TTR("Continue"), KEY_F12), DEBUG_CONTINUE);

editor/script_editor_debugger.cpp

@@ -2139,11 +2139,13 @@ ScriptEditorDebugger::ScriptEditorDebugger(EditorNode *p_editor) {
 		step = memnew(ToolButton);
 		hbc->add_child(step);
 		step->set_tooltip(TTR("Step Into"));
+		step->set_shortcut(ED_GET_SHORTCUT("debugger/step_into"));
 		step->connect("pressed", this, "debug_step");
 
 		next = memnew(ToolButton);
 		hbc->add_child(next);
 		next->set_tooltip(TTR("Step Over"));
+		next->set_shortcut(ED_GET_SHORTCUT("debugger/step_over"));
 		next->connect("pressed", this, "debug_next");
 
 		hbc->add_child(memnew(VSeparator));
@@ -2151,11 +2153,13 @@ ScriptEditorDebugger::ScriptEditorDebugger(EditorNode *p_editor) {
 		dobreak = memnew(ToolButton);
 		hbc->add_child(dobreak);
 		dobreak->set_tooltip(TTR("Break"));
+		dobreak->set_shortcut(ED_GET_SHORTCUT("debugger/break"));
 		dobreak->connect("pressed", this, "debug_break");
 
 		docontinue = memnew(ToolButton);
 		hbc->add_child(docontinue);
 		docontinue->set_tooltip(TTR("Continue"));
+		docontinue->set_shortcut(ED_GET_SHORTCUT("debugger/continue"));
 		docontinue->connect("pressed", this, "debug_continue");
 
 		back = memnew(Button);