Mariaex crashes when it can't encode a parameter

[josevalim]

Here is a test case:

  test "encoding bad parameters", context do
    query("SELECT 1", [:badparam])
  end

I have tried fixing this but, since parameters are only encoded later, we need a way to abort the current query and tell the client an error occurred. I am aware this mechanism exists for Postgrex so we can look there for inspiration.