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_yield_nodes.cpp

@@ -50,6 +50,7 @@ bool VisualScriptYield::has_input_sequence_port() const {
 int VisualScriptYield::get_input_value_port_count() const {
 	return 0;
 }
+
 int VisualScriptYield::get_output_value_port_count() const {
 	return 0;
 }
@@ -288,6 +289,7 @@ int VisualScriptYieldSignal::get_input_value_port_count() const {
 	else
 		return 0;
 }
+
 int VisualScriptYieldSignal::get_output_value_port_count() const {
 	MethodInfo sr;
 
@@ -357,6 +359,7 @@ void VisualScriptYieldSignal::set_signal(const StringName &p_type) {
 	_change_notify();
 	ports_changed_notify();
 }
+
 StringName VisualScriptYieldSignal::get_signal() const {
 	return signal;
 }
@@ -543,6 +546,7 @@ VisualScriptNodeInstance *VisualScriptYieldSignal::instance(VisualScriptInstance
 	instance->output_args = get_output_value_port_count();
 	return instance;
 }
+
 VisualScriptYieldSignal::VisualScriptYieldSignal() {
 	call_mode = CALL_MODE_SELF;
 	base_type = "Object";