Feature/add ssl support

Enable SSL support on the TCP transport, tested & working against logstash-12.1 input configured like this:

  tcp {
    type => "tcp-plain"
    host => "0.0.0.0"
    port => "5959"

    ssl_enable => true
    codec =>   oldlogstashjson { }
    ssl_verify => false
    ssl_cacert => '/etc/logstash/cacert.pem'
    ssl_cert => '/etc/logstash/logstash.crt'
    ssl_key => '/etc/logstash/logstash.key'
  }


Configuration in beaver is simple:

[beaver]
tcp_host = remote_logstash_server.localnet
tcp_port = 5959
tcp_ssl_enabled = True