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/message/draft.go

@@ -0,0 +1,67 @@
+package message
+
+import (
+	"context"
+
+	"github.com/go-faster/errors"
+
+	"go.mau.fi/mautrix-telegram/pkg/gotd/telegram/message/entity"
+	"go.mau.fi/mautrix-telegram/pkg/gotd/telegram/message/styling"
+	"go.mau.fi/mautrix-telegram/pkg/gotd/tg"
+)
+
+func (b *Builder) saveDraftRequest(
+	peer tg.InputPeerClass,
+	msg string,
+	entities []tg.MessageEntityClass,
+) *tg.MessagesSaveDraftRequest {
+	return &tg.MessagesSaveDraftRequest{
+		NoWebpage: b.noWebpage,
+		Peer:      peer,
+		ReplyTo:   b.replyTo,
+		Message:   msg,
+		Entities:  entities,
+	}
+}
+
+// ClearDraft clears draft.
+// Also, you can use Clear() builder option with any other message send method.
+//
+// See https://core.telegram.org/api/drafts#clearing-drafts.
+func (b *Builder) ClearDraft(ctx context.Context) error {
+	p, err := b.peer(ctx)
+	if err != nil {
+		return errors.Wrap(err, "peer")
+	}
+
+	return b.sender.saveDraft(ctx, &tg.MessagesSaveDraftRequest{Peer: p})
+}
+
+// SaveDraft saves given message as draft.
+//
+// See https://core.telegram.org/api/drafts#saving-drafts.
+func (b *Builder) SaveDraft(ctx context.Context, msg string) error {
+	p, err := b.peer(ctx)
+	if err != nil {
+		return errors.Wrap(err, "peer")
+	}
+
+	return b.sender.saveDraft(ctx, b.saveDraftRequest(p, msg, nil))
+}
+
+// SaveStyledDraft saves given styled message as draft.
+//
+// See https://core.telegram.org/api/drafts#saving-drafts.
+func (b *Builder) SaveStyledDraft(ctx context.Context, texts ...StyledTextOption) error {
+	p, err := b.peer(ctx)
+	if err != nil {
+		return errors.Wrap(err, "peer")
+	}
+
+	tb := entity.Builder{}
+	if err := styling.Perform(&tb, texts...); err != nil {
+		return err
+	}
+	msg, entities := tb.Complete()
+	return b.sender.saveDraft(ctx, b.saveDraftRequest(p, msg, entities))
+}