refactor(reaction): refactored to an abstract reaction class in prep for weak reactions

utils/WRL/test.cpp

@@ -0,0 +1,9 @@
+#include "weak_rate_library.h"
+#include <iostream>
+#include <array>
+#include <cstddef>
+
+int main() {
+  std::size_t totalBytes = sizeof(gridfire::rates::weak::UNIFIED_WEAK_DATA);
+  std::cout << "Total size in bytes of packed weak reaction data is : " << totalBytes/1.0e6 << " MB" << std::endl;
+}