add splitter filters to ui

src/lib/sim/BeltSystem.cpp

@@ -89,6 +89,22 @@ void BeltSystem::setSplitterFilters(QPoint tile,
     it->second.filterB = filterB;
 }
 
+std::optional<BeltSystem::SplitterInfo> BeltSystem::getSplitterInfo(QPoint tile) const
+{
+    const std::map<std::pair<int, int>, SplitterTile>::const_iterator it =
+        m_splitters.find(key(tile));
+    if (it == m_splitters.end())
+    {
+        return std::nullopt;
+    }
+    return SplitterInfo{
+        it->second.outputA,
+        it->second.outputB,
+        it->second.filterA,
+        it->second.filterB
+    };
+}
+
 // ---------------------------------------------------------------------------
 // Port interface
 // ---------------------------------------------------------------------------