Style: Enforce separation line between function definitions

I couldn't find a tool that enforces it, so I went the manual route:
```
find -name "thirdparty" -prune \
  -o -name "*.cpp" -o -name "*.h" -o -name "*.m" -o -name "*.mm" \
  -o -name "*.glsl" > files
perl -0777 -pi -e 's/\n}\n([^#])/\n}\n\n\1/g' $(cat files)
misc/scripts/fix_style.sh -c
```

This adds a newline after all `}` on the first column, unless they
are followed by `#` (typically `#endif`). This leads to having lots
of places with two lines between function/class definitions, but
clang-format then fixes it as we enforce max one line of separation.

This doesn't fix potential occurrences of function definitions which
are indented (e.g. for a helper class defined in a .cpp), but it's
better than nothing. Also can't be made to run easily on CI/hooks so
we'll have to be careful with new code.

Part of #33027.

modules/visual_script/visual_script_editor.cpp

@@ -1002,6 +1002,7 @@ void VisualScriptEditor::_update_node_size(int p_id) {
 	if (Object::cast_to<Control>(node))
 		Object::cast_to<Control>(node)->set_size(Vector2(1, 1)); //shrink if text is smaller
 }
+
 void VisualScriptEditor::_port_name_focus_out(const Node *p_name_box, int p_id, int p_port, bool is_input) {
 	StringName func = _get_function_of_node(p_id);