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/mtproxy/secret_test.go

@@ -0,0 +1,42 @@
+package mtproxy
+
+import (
+	"encoding/hex"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestParseSecret(t *testing.T) {
+	tests := []struct {
+		name    string
+		secret  string
+		want    SecretType
+		wantErr bool
+	}{
+		{"Simple", "52a493bdfb90eea55739eabff2d92a14", Simple, false},
+		{"Secured", "ddf05fb7acb549be047a7c585116581418", Secured, false},
+		{"Secured", "eef05fb7acb549be047a7c585116581418", Secured, false},
+		{"TLS-google.com", "ee852380f362a09343efb4690c4e17862e676f6f676c652e636f6d", TLS, false},
+		{"TLS-bing.com", "eedf71035a8ed48a623d8e83e66aec4d0562696e672e636f6d", TLS, false},
+		{"TLS-yandex.ru", "ee7cea5c13d65f12fd808de70ddcc8d3a979616e6465782e7275", TLS, false},
+		{"Bad", "52a493bdfb90eea55739eabff2d92a", 0, true},
+		{"Bad", "52a493bdfb90eea55739eabff2d92a1422", 0, true},
+		{"Bad", "dd", 0, true},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			s, err := hex.DecodeString(tt.secret)
+			require.NoError(t, err)
+
+			got, err := ParseSecret(s)
+			if (err != nil) != tt.wantErr {
+				t.Errorf("ParseSecret() error = %v, wantErr %v", err, tt.wantErr)
+				return
+			}
+			if err == nil {
+				require.Equal(t, tt.want, got.Type)
+			}
+		})
+	}
+}