Swap tree - detect missing edge cases for failed swaps

[dvinubius]

1. https://www.ao.link/#/message/7_9VWs3coNRk_XK99zdtEKzt2PABvProjhB17ug8VRE
2. https://www.ao.link/#/message/WKC29Ss3UbO9CEbwA9e3XDM6L97RLUeHSiXsLUVYTvQ

The initial transfer had a 'Transfer-Error' in 1. and a missing Credit-Notice (unpushed message) in 2.

They are currently not recognized / displayed in the swap tree on the /swap/message_id page