Add temporary variables

Enables easier use of values returned by macro segments.
For example, this enables the user to extract the user name of a new
Twitch follower and change a text sources settings accordingly

src/advanced-scene-switcher.cpp

@@ -325,6 +325,9 @@ void SwitcherData::SetPreconditions()
 	cursorPosChanged = cursorPos.first != switcher->lastCursorPos.first ||
 			   cursorPos.second != switcher->lastCursorPos.second;
 	lastCursorPos = GetCursorPos();
+
+	// Macro
+	InvalidateMacroTempVarValues();
 }
 
 void ClearWebsocketMessages();