Use Jolt Physics by default in newly created projects

This also adds infrastructure to make specific settings the default, but only
in projects created after this point (so that existing projects
are not affected). This can be used for progressive upgrades in the future.

This applies to both the project creation dialog and creating projects
through the command line using `touch project.godot`.

editor/editor_node.h

@@ -768,6 +768,9 @@ public:
 	static bool immediate_confirmation_dialog(const String &p_text, const String &p_ok_text = TTR("Ok"), const String &p_cancel_text = TTR("Cancel"), uint32_t p_wrap_width = 0);
 
 	static bool is_cmdline_mode();
+
+	static HashMap<String, Variant> get_initial_settings();
+
 	static void cleanup();
 
 	EditorPluginList *get_editor_plugins_force_input_forwarding() { return editor_plugins_force_input_forwarding; }