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/builder.go

@@ -0,0 +1,133 @@
+package message
+
+import (
+	"time"
+
+	"go.mau.fi/mautrix-telegram/pkg/gotd/telegram/message/markup"
+	"go.mau.fi/mautrix-telegram/pkg/gotd/telegram/message/peer"
+	"go.mau.fi/mautrix-telegram/pkg/gotd/tg"
+)
+
+type peerPromise = peer.Promise
+
+// CloneBuilder returns copy of message Builder inside RequestBuilder.
+func (b *RequestBuilder) CloneBuilder() *Builder {
+	return b.Builder.copy()
+}
+
+// Builder is a message builder.
+type Builder struct {
+	// Sender to use.
+	sender *Sender
+	// The destination where the message will be sent.
+	peer peerPromise
+
+	// Set this flag to disable generation of the webpage preview.
+	noWebpage bool
+	// Send this message silently (no notifications for the receivers).
+	silent bool
+	// Send this message as background message.
+	background bool
+	// Clear the draft field.
+	clearDraft bool
+	// noForwards whether that sent message cannot be forwarded.
+	noForwards bool
+
+	// The reply target.
+	replyTo tg.InputReplyToClass
+	// Reply markup for sending bot buttons.
+	replyMarkup tg.ReplyMarkupClass
+	// Scheduled message date for scheduled messages.
+	scheduleDate int
+
+	// sendAs sets peer to send message as it.
+	sendAs tg.InputPeerClass
+}
+
+func (b *Builder) copy() *Builder {
+	if b == nil {
+		return nil
+	}
+
+	r := *b
+	return &r
+}
+
+// Silent sets flag to send this message silently (no notifications for the receivers).
+func (b *Builder) Silent() *Builder {
+	b.silent = true
+	return b
+}
+
+// Background sets flag to send this message as background message.
+func (b *Builder) Background() *Builder {
+	b.background = true
+	return b
+}
+
+// Clear sets flag to clear the draft field.
+func (b *Builder) Clear() *Builder {
+	b.clearDraft = true
+	return b
+}
+
+// Reply sets message ID to reply.
+func (b *Builder) Reply(id int) *Builder {
+	b.replyTo = &tg.InputReplyToMessage{
+		ReplyToMsgID: id,
+	}
+	return b
+}
+
+// ReplyMsg sets message to reply.
+func (b *Builder) ReplyMsg(msg tg.MessageClass) *Builder {
+	return b.Reply(msg.GetID())
+}
+
+// ScheduleTS sets scheduled message timestamp for scheduled messages.
+func (b *Builder) ScheduleTS(date int) *Builder {
+	b.scheduleDate = date
+	return b
+}
+
+// Schedule sets scheduled message date for scheduled messages.
+func (b *Builder) Schedule(date time.Time) *Builder {
+	return b.ScheduleTS(int(date.Unix()))
+}
+
+// NoWebpage sets flag to disable generation of the webpage preview.
+func (b *Builder) NoWebpage() *Builder {
+	b.noWebpage = true
+	return b
+}
+
+// NoForwards whether that sent message cannot be forwarded.
+//
+// See https://telegram.org/blog/protected-content-delete-by-date-and-more#protected-content-in-groups-and-channels.
+func (b *Builder) NoForwards() *Builder {
+	b.noForwards = true
+	return b
+}
+
+// Markup sets reply markup for sending bot buttons.
+//
+// NB: markup will not be used, if you send multiple media attachments.
+func (b *Builder) Markup(m tg.ReplyMarkupClass) *Builder {
+	b.replyMarkup = m
+	return b
+}
+
+// Row sets single row keyboard markup  for sending bot buttons.
+//
+// NB: markup will not be used, if you send multiple media attachments.
+func (b *Builder) Row(buttons ...tg.KeyboardButtonClass) *Builder {
+	return b.Markup(markup.InlineRow(buttons...))
+}
+
+// SendAs sets peer to send as.
+//
+// See https://telegram.org/blog/protected-content-delete-by-date-and-more#anonymous-posting-in-public-groups.
+func (b *Builder) SendAs(p tg.InputPeerClass) *Builder {
+	b.sendAs = p
+	return b
+}