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/gen/generator_test.go

@@ -0,0 +1,68 @@
+package gen
+
+import (
+	"bytes"
+	"go/format"
+	"os"
+	"testing"
+
+	"github.com/go-faster/errors"
+
+	"github.com/gotd/tl"
+)
+
+type formattedSource struct{}
+
+func (t formattedSource) WriteFile(name string, content []byte) error {
+	if name == "" {
+		return errors.New("name is blank")
+	}
+	_, err := format.Source(content)
+	return err
+}
+
+func TestGenerator(t *testing.T) {
+	data, err := os.ReadFile("_testdata/example.tl")
+	if err != nil {
+		t.Fatal(err)
+	}
+	schema, err := tl.Parse(bytes.NewReader(data))
+	if err != nil {
+		t.Fatal(err)
+	}
+	g, err := NewGenerator(schema, GeneratorOptions{
+		GenerateFlags: GenerateFlags{
+			Client:   true,
+			Registry: true,
+			Server:   true,
+			Handlers: true,
+			GetSet:   true,
+			Mapping:  true,
+			Slices:   true,
+		},
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := g.WriteSource(formattedSource{}, "pkg", Template()); err != nil {
+		t.Fatal(err)
+	}
+}
+
+func TestGeneratorTelegram(t *testing.T) {
+	data, err := os.ReadFile("_testdata/telegram.tl")
+	if err != nil {
+		t.Fatal(err)
+	}
+	schema, err := tl.Parse(bytes.NewReader(data))
+	if err != nil {
+		t.Fatal(err)
+	}
+	g, err := NewGenerator(schema, GeneratorOptions{DocBaseURL: "https://core.telegram.org/"})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := g.WriteSource(formattedSource{}, "pkg", Template()); err != nil {
+		t.Fatal(err)
+	}
+}