banlist: add more banlist infos to log / add GUI signal
banlist: add more banlist infos to log / add GUI signal

- to match the peers.dat handling also supply a debug.log entry for how
  many entries were loaded from banlist.dat and how long it took
- add a GUI init message for loading the banlist (same as with peers.dat)

- move the same message for peers.dat upwards in the code, to be able to
  reuse the timing variable nStart and also just log, if our read from
  peers.dat didn't fail

Bitcoin-com/BUcash,Bitcoin-com/BUcash,BitcoinUnlimited/BitcoinUnlimited,Bitcoin-com/BUcash,ftrader-bitcoinunlimited/hardfork_prototype_1_mvf-bu,BitcoinUnlimited/BitcoinUnlimited,ftrader-bitcoinunlimited/hardfork_prototype_1_mvf-bu,BTCfork/hardfork_prototype_1_mvf-bu,ftrader-bitcoinunlimited/hardfork_prototype_1_mvf-bu,ftrader-bitcoinunlimited/hardfork_prototype_1_mvf-bu,Justaphf/BitcoinUnlimited,ftrader-bitcoinunlimited/hardfork_prototype_1_mvf-bu,BTCfork/hardfork_prototype_1_mvf-bu,BTCfork/hardfork_prototype_1_mvf-bu,BitcoinUnlimited/BitcoinUnlimited,Justaphf/BitcoinUnlimited,Bitcoin-com/BUcash,BTCfork/hardfork_prototype_1_mvf-bu,Justaphf/BitcoinUnlimited,Bitcoin-com/BUcash,Justaphf/BitcoinUnlimited,BTCfork/hardfork_prototype_1_mvf-bu,BitcoinUnlimited/BitcoinUnlimited,BitcoinUnlimited/BitcoinUnlimited,ftrader-bitcoinunlimited/hardfork_prototype_1_mvf-bu,Justaphf/BitcoinUnlimited,Justaphf/BitcoinUnlimited,BitcoinUnlimited/BitcoinUnlimited,BTCfork/hardfork_prototype_1_mvf-bu,Bitcoin-com/BUcash