ObjLoading: Load common ipaks depending on SP/MP/ZM for every zone and make sure to not double load them

src/ObjLoading/ObjContainer/IPak/IPak.cpp

@@ -157,7 +157,7 @@ public:
 
     std::string GetName() override
     {
-        return utils::Path::GetFilename(m_path);
+        return utils::Path::GetFilenameWithoutExtension(m_path);
     }
 
     bool Initialize()

src/ObjLoading/ObjContainer/ObjContainerRepository.h

@@ -68,7 +68,7 @@ public:
         }
     }
 
-    IObjContainer* GetContainerByName(const std::string& name)
+    ContainerType* GetContainerByName(const std::string& name)
     {
         auto foundEntry = std::find_if(m_containers.begin(), m_containers.end(), [name](ObjContainerEntry& entry) -> bool
             {