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/file.go

@@ -0,0 +1,21 @@
+package message
+
+import "go.mau.fi/mautrix-telegram/pkg/gotd/tg"
+
+// FileLocation is an abstraction of Telegram file location.
+type FileLocation interface {
+	GetID() (value int64)
+	GetAccessHash() (value int64)
+	GetFileReference() (value []byte)
+}
+
+func inputDocuments(files ...FileLocation) (r []tg.InputDocumentClass) {
+	r = make([]tg.InputDocumentClass, len(files))
+	for i := range files {
+		v := new(tg.InputDocument)
+		v.FillFrom(files[i])
+		r[i] = v
+	}
+
+	return
+}