Implement a syscall to retreive the transaction origin.

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Signed-off-by: Cyrill Leutwiler <bigcyrill@hotmail.com>
Signed-off-by: xermicus <cyrill@parity.io>
Co-authored-by: GitHub Action <action@github.com>
Co-authored-by: command-bot <>
Co-authored-by: Alexander Theißen <alex.theissen@me.com>