ZoneLoading: Add ZoneMemory and the possibility to unload zones and their memory

src/ZoneCommon/Zone/ZoneMemory.h

@@ -0,0 +1,19 @@
+#pragma once
+
+#include "Zone/XBlock.h"
+#include <vector>
+
+class ZoneMemory
+{
+    std::vector<XBlock*> m_blocks;
+    std::vector<void*> m_allocations;
+
+public:
+    ZoneMemory();
+    ~ZoneMemory();
+
+    void AddBlock(XBlock* block);
+
+    void* Alloc(size_t size);
+    char* Dup(const char* str);
+};