[Rework] Rework lua_tcp to allow TCP dialog
[Rework] Rework lua_tcp to allow TCP dialog

- Now, lua_tcp has a chain of read and write events that are processed
  in order
- The old API wasn't touched, however, new style API will be possible
- Partial lua_tcp might be broken, so I need to revisit all plugins that
  use lua_tcp

Issue: #1224

AlexeySa/rspamd,AlexeySa/rspamd,AlexeySa/rspamd,AlexeySa/rspamd,AlexeySa/rspamd,AlexeySa/rspamd,AlexeySa/rspamd,AlexeySa/rspamd,AlexeySa/rspamd