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/telegram/send_message.go

@@ -0,0 +1,25 @@
+package telegram
+
+import (
+	"context"
+
+	"go.mau.fi/mautrix-telegram/pkg/gotd/tg"
+)
+
+// SendMessage sends message to peer.
+//
+// Deprecated: use helpers like message.NewSender.
+func (c *Client) SendMessage(ctx context.Context, req *tg.MessagesSendMessageRequest) error {
+	if req.RandomID == 0 {
+		id, err := c.RandInt64()
+		if err != nil {
+			return err
+		}
+		req.RandomID = id
+	}
+	updates, err := c.tg.MessagesSendMessage(ctx, req)
+	if err != nil {
+		return err
+	}
+	return c.processUpdates(updates)
+}