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/mtproto/encrypt_test.go

@@ -0,0 +1,51 @@
+package mtproto
+
+import (
+	"fmt"
+	"testing"
+	"time"
+
+	"go.uber.org/zap"
+
+	"github.com/gotd/neo"
+
+	"go.mau.fi/mautrix-telegram/pkg/gotd/bin"
+	"go.mau.fi/mautrix-telegram/pkg/gotd/crypto"
+	"go.mau.fi/mautrix-telegram/pkg/gotd/testutil"
+)
+
+func benchEncryption(b *testing.B, c *Conn, n int) {
+	b.Helper()
+
+	buf := &bin.Buffer{Buf: make([]byte, 0, n)}
+	p := testPayload{Data: make([]byte, n-4)}
+	b.ReportAllocs()
+	b.SetBytes(int64(n))
+	b.ResetTimer()
+
+	for i := 0; i < b.N; i++ {
+		buf.Reset()
+		if err := c.newEncryptedMessage(12345, 0, p, buf); err != nil {
+			b.Fatal(err)
+		}
+	}
+}
+
+func BenchmarkEncryption(b *testing.B) {
+	c := &Conn{
+		rand:              Zero{},
+		log:               zap.NewNop(),
+		cipher:            crypto.NewClientCipher(Zero{}),
+		clock:             neo.NewTime(time.Now()),
+		compressThreshold: -1,
+	}
+	for i := 0; i < 256; i++ {
+		c.authKey.Value[i] = byte(i)
+	}
+
+	for _, payload := range testutil.Payloads() {
+		b.Run(fmt.Sprintf("%db", payload), func(b *testing.B) {
+			benchEncryption(b, c, payload)
+		})
+	}
+}