DiscIO: Remove C/I/S prefixes from class names

These prefixes were inconsistent with the rest of Dolphin.

I'm also renaming VolumeWiiCrypted to VolumeWii because of 1113b13.

Source/Core/DiscIO/Blob.cpp

@@ -173,7 +173,7 @@ u32 SectorReader::ReadChunk(u8* buffer, u64 chunk_num)
   return 0;
 }
 
-std::unique_ptr<IBlobReader> CreateBlobReader(const std::string& filename)
+std::unique_ptr<BlobReader> CreateBlobReader(const std::string& filename)
 {
   if (cdio_is_cdrom(filename))
     return DriveReader::Create(filename);