add flatbuffers support and initial rewrite

Signed-off-by: Folling <mail@folling.io>

include/ikarus/values/value_cardinality.h

@@ -0,0 +1,23 @@
+#pragma once
+
+/// \file value_cardinality.h
+/// \author Folling <folling@ikarus.world>
+
+/// \addtogroup values Values
+/// @{
+
+#include <ikarus/macros.h>
+
+IKARUS_BEGIN_HEADER
+
+/// \brief The cardinality of a value.
+enum IkarusValueCardinality {
+    /// \brief Only contains one datapoint
+    IkarusValueCardinality_Single,
+    /// \brief Contains any number of datapoints
+    IkarusValueCardinality_List
+};
+
+IKARUS_END_HEADER
+
+/// @}