PPather: MpqFileStream over SFileExtractFile

[Xian55]

Changes:

• Split StormDll into separate classes.
• Using LibraryImport over DllImport.
• Use MpqFileStream over SFileExtractFile API.

Key difference:

• Instead of extracting the given file into storage(HDD or SSD), rather access it in memory.
• Reduce stream load times and cpu usage.

Later on further improvements:

• Find a way to use ArrayPool over raw arrays when using MpqFileStream.ReadAllBytes
• Sadly, it only gives the performance benefit, when using MpqFileStream.ReadAllBytes.
• There's a Buffer copy when instantiating MemoryStream
• Chunked/Buffered stream reading results slower process times :(

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Tested with x86 and x64 builds as well.