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/tg/tl_null_gen.go

@@ -0,0 +1,129 @@
+// Code generated by gotdgen, DO NOT EDIT.
+
+package tg
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"sort"
+	"strings"
+
+	"go.uber.org/multierr"
+
+	"go.mau.fi/mautrix-telegram/pkg/gotd/bin"
+	"go.mau.fi/mautrix-telegram/pkg/gotd/tdjson"
+	"go.mau.fi/mautrix-telegram/pkg/gotd/tdp"
+	"go.mau.fi/mautrix-telegram/pkg/gotd/tgerr"
+)
+
+// No-op definition for keeping imports.
+var (
+	_ = bin.Buffer{}
+	_ = context.Background()
+	_ = fmt.Stringer(nil)
+	_ = strings.Builder{}
+	_ = errors.Is
+	_ = multierr.AppendInto
+	_ = sort.Ints
+	_ = tdp.Format
+	_ = tgerr.Error{}
+	_ = tdjson.Encoder{}
+)
+
+// Null represents TL type `null#56730bcc`.
+// Corresponds to an arbitrary empty object.
+//
+// See https://core.telegram.org/constructor/null for reference.
+type Null struct {
+}
+
+// NullTypeID is TL type id of Null.
+const NullTypeID = 0x56730bcc
+
+// Ensuring interfaces in compile-time for Null.
+var (
+	_ bin.Encoder     = &Null{}
+	_ bin.Decoder     = &Null{}
+	_ bin.BareEncoder = &Null{}
+	_ bin.BareDecoder = &Null{}
+)
+
+func (n *Null) Zero() bool {
+	if n == nil {
+		return true
+	}
+
+	return true
+}
+
+// String implements fmt.Stringer.
+func (n *Null) String() string {
+	if n == nil {
+		return "Null(nil)"
+	}
+	type Alias Null
+	return fmt.Sprintf("Null%+v", Alias(*n))
+}
+
+// TypeID returns type id in TL schema.
+//
+// See https://core.telegram.org/mtproto/TL-tl#remarks.
+func (*Null) TypeID() uint32 {
+	return NullTypeID
+}
+
+// TypeName returns name of type in TL schema.
+func (*Null) TypeName() string {
+	return "null"
+}
+
+// TypeInfo returns info about TL type.
+func (n *Null) TypeInfo() tdp.Type {
+	typ := tdp.Type{
+		Name: "null",
+		ID:   NullTypeID,
+	}
+	if n == nil {
+		typ.Null = true
+		return typ
+	}
+	typ.Fields = []tdp.Field{}
+	return typ
+}
+
+// Encode implements bin.Encoder.
+func (n *Null) Encode(b *bin.Buffer) error {
+	if n == nil {
+		return fmt.Errorf("can't encode null#56730bcc as nil")
+	}
+	b.PutID(NullTypeID)
+	return n.EncodeBare(b)
+}
+
+// EncodeBare implements bin.BareEncoder.
+func (n *Null) EncodeBare(b *bin.Buffer) error {
+	if n == nil {
+		return fmt.Errorf("can't encode null#56730bcc as nil")
+	}
+	return nil
+}
+
+// Decode implements bin.Decoder.
+func (n *Null) Decode(b *bin.Buffer) error {
+	if n == nil {
+		return fmt.Errorf("can't decode null#56730bcc to nil")
+	}
+	if err := b.ConsumeID(NullTypeID); err != nil {
+		return fmt.Errorf("unable to decode null#56730bcc: %w", err)
+	}
+	return n.DecodeBare(b)
+}
+
+// DecodeBare implements bin.BareDecoder.
+func (n *Null) DecodeBare(b *bin.Buffer) error {
+	if n == nil {
+		return fmt.Errorf("can't decode null#56730bcc to nil")
+	}
+	return nil
+}