edk2: Buffer overflows in PartitionDxe and UdfDxe with long file names and invalid UDF media

Buffer overflows were discovered in UDF-related codes under MdeModulePkg\Universal\Disk\PartitionDxe\Udf.c and MdeModulePkg\Universal\Disk\UdfDxe, which could be triggered with long file names or invalid formatted UDF media...