Generate extra data at `Mid0008` by providing the desired mid to subscribe

[Rickedb]

Is there a way to generate the 006000080010 1201001310000000000000000000000000000001 with new Midxxxx().Pack()?
At the moment, I just send it as plain text.

Originally posted by @AndreasReitberger in #101 (comment)

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Nowadays the only possible way is to set ExtraData as plain text and the user should handle paddings and rules by itself.