Handle utf-16 encoding gracefully when querying Snowflake

[notactuallytreyanastasio]

This stemmed from an issue we saw in production, a result we were
getting included some garbled characters because of a UTF-8 and UTF-16
difference.

We were getting the string:

"CVS Pharmacy®"

Now, Â = U+00C2 and ® = U+00AE in UTF-8.

However, what we really wanted was:

"CVS Pharmacy®"

As the  character is a mistaken extra byte.

Here, we introduce a function to properly handle this and return the
desired results using the latin1 encoding with UTF-8.

I have tried a couple ways of going about testing this, but the coverage
so far does not allow me an easy way to even hit this branch of the
functions in result or snowflex itself. I will confer with someone else
to get a real test written.

JIRA ticket is AUTO-4025

Here is validation run on this using just iex to demonstrate:

iex(1)> string = "CVS Pharmacy®"
"CVS Pharmacy®"
iex(2)>
nil
iex(3)> defmodule Convert do
...(3)>   def parse(string) do
...(3)>     string
...(3)>     |> to_charlist
...(3)>     |> handle_encoding
...(3)>   end
...(3)>
...(3)>   defp handle_encoding(data) when is_list(data) do
...(3)>     raw = :erlang.list_to_binary(data)
...(3)>     case :unicode.characters_to_binary(raw) do
...(3)>       utf8 when is_binary(utf8) -> utf8
...(3)>       _ -> :unicode.characters_to_binary(raw, :latin1)
...(3)>     end
...(3)>   end
...(3)>
...(3)>   defp handle_encoding(data), do: data
...(3)> end
{:module, Convert,
 <<70, 79, 82, 49, 0, 0, 6, 240, 66, 69, 65, 77, 65, 116, 85, 56, 0, 0, 0, 236,
   0, 0, 0, 21, 14, 69, 108, 105, 120, 105, 114, 46, 67, 111, 110, 118, 101,
   114, 116, 8, 95, 95, 105, 110, 102, 111, 95, ...>>, {:handle_encoding, 1}}
iex(4)>
nil
iex(5)> IO.puts Convert.parse(string)
CVS Pharmacy®
:ok

[superhawk610]

Could be helpful to add a similar test for db_connection

[notactuallytreyanastasio]

@superhawk610 will do good eye 👍