move gotd fork into repo. (#111)

- update to latest telegram layer
- remove some references to fields in tg.Entities that don't exist in
the schema
- originally added here:
https://github.com/beeper/td/commit/820929062a2ba0104397bc01235ab58a9cff780e
  - referenced here
-
https://github.com/mautrix/telegramgo/commit/124f0967ed195b5a380c9bd02e170ada9710dde3
-
https://github.com/mautrix/telegramgo/commit/4205047aab2e0639217148b5d125bfaab668bd8e

pkg/gotd/session/session_test.go

@@ -0,0 +1,37 @@
+package session
+
+import (
+	"bytes"
+	"context"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func testStorage(storage Storage) func(t *testing.T) {
+	ctx := context.Background()
+	loader := Loader{
+		Storage: storage,
+	}
+
+	return func(t *testing.T) {
+		a := require.New(t)
+
+		_, err := loader.Load(ctx)
+		a.ErrorIs(err, ErrNotFound)
+
+		data := &Data{
+			Config:    Config{},
+			DC:        2,
+			Addr:      "localhost:8080",
+			AuthKey:   bytes.Repeat([]byte{'a'}, 256),
+			AuthKeyID: []byte("gotd1337"),
+			Salt:      10,
+		}
+		a.NoError(loader.Save(ctx, data))
+
+		gotData, err := loader.Load(ctx)
+		a.NoError(err)
+		require.Equal(t, data, gotData)
+	}
+}