add new data wrapper helper type

src/fsfw/util/dataWrapper.h

@@ -0,0 +1,52 @@
+#ifndef FSFW_UTIL_DATAWRAPPER_H
+#define FSFW_UTIL_DATAWRAPPER_H
+
+#include <cstddef>
+#include <cstdint>
+#include <utility>
+
+#include "fsfw/serialize.h"
+
+namespace util {
+
+struct RawData {
+  const uint8_t* data;
+  size_t len;
+};
+
+enum DataTypes { RAW, SERIALIZABLE };
+
+union DataUnion {
+  RawData raw;
+  SerializeIF* serializable;
+};
+
+struct DataWrapper {
+  DataTypes type;
+  DataUnion dataUnion;
+  using BufPairT = std::pair<const uint8_t*, size_t>;
+
+  [[nodiscard]] size_t getLength() const {
+    if (type == DataTypes::RAW) {
+      return dataUnion.raw.len;
+    } else if (type == DataTypes::SERIALIZABLE and dataUnion.serializable != nullptr) {
+      return dataUnion.serializable->getSerializedSize();
+    }
+    return 0;
+  }
+
+  void setRawData(BufPairT bufPair) {
+    type = DataTypes::RAW;
+    dataUnion.raw.data = bufPair.first;
+    dataUnion.raw.len = bufPair.second;
+  }
+
+  void setSerializable(SerializeIF& serializable) {
+    type = DataTypes::SERIALIZABLE;
+    dataUnion.serializable = &serializable;
+  }
+};
+
+}  // namespace util
+
+#endif  // FSFW_UTIL_DATAWRAPPER_H