add logging of Tx hex

[ghost]

It will help with investigation of the missing tx issues if we log the tx hex at the point they leave Bisq.

Related to #4878 (comment)

Here is an example of the logging (the first line is new):

    Dec-03 09:51:58.864 [JavaFX Application Thread] INFO  b.c.btc.wallet.TxBroadcaster: Txid: 64af6af087d1fab329e1be72a616b71720ed2c5d3c8c7061be6c4d1899181c9f hex: 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 
    Dec-03 09:51:58.867 [JavaFX Application Thread] INFO  o.b.core.TransactionBroadcast: Waiting for 1 peers required for broadcast, we have 1 ... 
    Dec-03 09:51:58.869 [JavaFX Application Thread] INFO  o.b.core.TransactionBroadcast: broadcastTransaction: We have 1 peers, adding 64af6af087d1fab329e1be72a616b71720ed2c5d3c8c7061be6c4d1899181c9f to the memory pool 
    Dec-03 09:51:58.869 [JavaFX Application Thread] INFO  o.b.core.TransactionBroadcast: Sending to 1 peers, will wait for 0, sending to: Peer{[127.0.0.1]:18444, version=70015, subVer=/Satoshi:0.19.0.1/, services=1037 (NETWORK, BLOOM, WITNESS, NETWORK_LIMITED), time=2020-12-03 09:50:37, height=4672} 
    Dec-03 09:51:58.876 [JavaFX Application Thread] ERROR b.d.m.o.w.ManualPayoutTxWindow: onSuccess 

[ripcurlx]

utACK