Add auto-reconnect of cli_wallet to golosd on losing connection

[zxcat]

Steps to reproduce

1. Run cli_wallet
2. Send any command, which use websocket, e.g. >>> get_block 123
3. Wait some time, websocket will disconnect silently
4. Send other websocket related command

Actual results From this point all websocket related commands will fail with

10 assert_exception: Assert Exception
!ec: websocket send failed: invalid state
    {"msg":"invalid state"}
    th_0  websocket.cpp:165 send_message

Expected results Command in step 4 and all following commands works fine

[VIM-Arcange]

@zxcat Does your cli_wallet connect to a local node (on same host/network) or a remote (public) node?

[zxcat]

@VIM-Arcange testing on remote nodes, they disconnect ws clients after some inactivity

[VIM-Arcange]

Then it looks like a problem of the remote site infrastructure, not cli_wallet This often happens when the node is behind nginx and nginx is not properly configured.

I have cli_wallet running in screen and connected to my own nodes. I do now experience such disconnection problems.

Anyway, this does not prevent from implementing some "re-connection" mechanism in cli_wallet.

[kotbegemot]

https://github.com/GolosChain/golos/pull/523