zetaclient : add PostOutboundTracker to ZetaRepo interface #4445
Description
PostOutboundTracker adds an outbound tracker once an outbound has been signed and broadcast by the TSS address
This transaction is needed so that , the other observers can know about broadcast and try to confirm it ,
The chain observers , handle this trasnaction in slighlty differnt mecahnims , the following pr adds a simple retry tfor btc
#4440
We should instead create a mechanism for this and use it for all chain clients; this can be part of ZetaRepo.PostOutboundTracker