P2P Service: Trading

[rodvar]

After this issue gets done, the UI can allow the user to trade using the androidNode app relying on.

Inbound trading messaging

• messages arrives, gets interpreted and consecuentially the service impacts the related repository/ies

Outboud trading messaging

there are 2 options here

• provide android foreground service (see docs) messaging service to communicate with the foreground service and then perform the push to the p2p network or
• use the same repository mechanism (this will need us to manage a state or status medatada for the trade POKO obj, so when the trade changed )

Regardless, this involves first understanding the messages coming from bisq 2 network and how to post them (@HenrikJannsen can help here)