SDK Fullnode panic

[thanhnguyennguyen]

Steps to reproduces:

• Point ws_url in SDK DEX configuration to websocket of fullnode
• Navigate to SDK UI, login with privatekey
  -> SDK fullnode panic
  

Note: everything is ok if we point ws_url to websocket of masternode

cc @pqv199x

[pqv199x]

A fullnode is not a masternode(cannot commit transaction), so it does not have enough configures such as coinbase address... to run some APIs.

1. Turn on AnnounceTxsFlag, --announce-txs, fullnode will try to commit tx as a masternode
   Or:
2. Turn off option Pending(tomox-sdk):
   opts := &bind.CallOpts{Pending: true}
   when calling API. This changing will force API function get state of latest block number instead of pending block number(API throws errors if AnnounceTxsFlag is not set)

[thanhnguyennguyen]

thank Vu 🙇‍♂️