Better parent version filtering; handle old fabric :P

Signed-off-by: TheKodeToad <TheKodeToad@proton.me>

launcher/Filter.cpp

@@ -16,6 +16,12 @@ bool ExactFilter::accepts(const QString& value)
     return value == pattern;
 }
 
+ExactIfPresentFilter::ExactIfPresentFilter(const QString& pattern) : pattern(pattern) {}
+bool ExactIfPresentFilter::accepts(const QString& value)
+{
+    return value.isEmpty() || value == pattern;
+}
+
 RegexpFilter::RegexpFilter(const QString& regexp, bool invert)
     :invert(invert)
 {