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/fileid/encode_test.go

@@ -0,0 +1,24 @@
+package fileid
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestFileIDEncodeDecode(t *testing.T) {
+	for name, input := range testData {
+		t.Run(name, func(t *testing.T) {
+			a := require.New(t)
+			fileID, err := DecodeFileID(input)
+			a.NoError(err)
+
+			output, err := EncodeFileID(fileID)
+			a.NoError(err)
+
+			decoded, err := DecodeFileID(output)
+			a.NoError(err)
+			a.Equal(fileID, decoded)
+		})
+	}
+}