Fix suggestions when using typespecs returning a remote type (#282)

As shown in the following code:

```
  defmodule Mod do
    @SPEC fun() :: NaiveDateTime.t()
    def fun(), do: NaiveDateTime.new(1, 2)

    def some do
      var = fun()
      var.h
      #    ^  suggestion here
    end
  end
```

It should be able to suggest from NaiveDateTime.

This wasn't working before because the `__aliases__` weren't being
handled:

```
iex(1)> Code.string_to_quoted("@SPEC fun() :: NaiveDateTime.t()")
{:ok,
 {:@, [line: 1],
  [
    {:spec, [line: 1],
     [
       {:"::", [line: 1],
        [
          {:fun, [line: 1], []},
          {{:., [line: 1], [{:__aliases__, [line: 1], [:NaiveDateTime]}, :t]},
           [line: 1], []}
        ]}
     ]}
  ]}}
```

lib/elixir_sense/core/binding.ex

@@ -1191,6 +1191,13 @@ defmodule ElixirSense.Core.Binding do
     expand_type(env, mod, atom, args, false)
   end
 
+  # remote user type
+  defp parse_type(env, {{:., _, [{:__aliases__, _, aliases}, atom]}, _, args}, _mod, _include_private)
+       when is_atom(atom) do
+    # do not propagate include_private when expanding remote types
+    expand_type(env, Module.concat(aliases), atom, args, false)
+  end
+
   # no_return
   defp parse_type(_env, {:no_return, _, _}, _, _include_private), do: :none
 

test/elixir_sense/suggestions_test.exs

@@ -3173,6 +3173,24 @@ defmodule ElixirSense.SuggestionsTest do
            ] = list
   end
 
+  test "suggest struct fields when metadata function evaluates to remote type" do
+    buffer = """
+    defmodule Mod do
+      @spec fun() :: NaiveDateTime.t()
+      def fun(), do: NaiveDateTime.new(1, 2)
+
+      def some do
+        var = fun()
+        var.h
+      end
+    end
+    """
+
+    list = ElixirSense.suggestions(buffer, 7, 10)
+
+    assert [%{name: "hour", origin: "NaiveDateTime"}] = list
+  end
+
   test "suggest struct fields when variable is struct" do
     buffer = """
     defmodule Abc do