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/_template/getset.tmpl

@@ -0,0 +1,48 @@
+{{- /*gotype: go.mau.fi/mautrix-telegram/pkg/gotd/gen.structDef*/ -}}
+{{ define "getset" }}{{ $s := . }}
+
+{{- range $f := $s.Fields }}{{ if ne ($f.Type) ("bin.Fields") }}
+{{ if $f.Conditional }}
+// Set{{ $f.Name }} sets value of {{ $f.Name }} conditional field.
+func ({{ $s.Receiver }} *{{ $s.Name }}) Set{{ $f.Name }}(value {{ template "print_type" $f }}) {
+{{- if $f.ConditionalBool }}
+    if value {
+        {{ $s.Receiver }}.{{ $f.ConditionalField }}.Set({{ $f.ConditionalIndex }})
+        {{ $s.Receiver }}.{{ $f.Name }} = true
+    } else {
+        {{ $s.Receiver }}.{{ $f.ConditionalField }}.Unset({{ $f.ConditionalIndex }})
+        {{ $s.Receiver }}.{{ $f.Name }} = false
+    }
+{{- else }}
+    {{ $s.Receiver }}.{{ $f.ConditionalField }}.Set({{ $f.ConditionalIndex }})
+    {{ $s.Receiver }}.{{ $f.Name }} = value
+{{- end }}
+}
+{{- end }}
+
+// Get{{ $f.Name }} returns value of {{ $f.Name }} {{ if $f.Conditional }}
+{{- if not ($f.ConditionalBool) }}conditional field and
+// boolean which is true if field was set.
+{{- else }}conditional field.
+{{- end }}
+{{- else }}field.
+{{- end }}
+func ({{ $s.Receiver }} *{{ $s.Name }}) {{ template "getter_func_type" $f }} {
+    if {{ $s.Receiver }} == nil {
+        return
+    }
+    {{- if $f.Conditional }}{{ if not ($f.ConditionalBool) }}
+    if !{{ $s.Receiver }}.{{ $f.ConditionalField }}.Has({{ $f.ConditionalIndex }}) {
+        return value, false
+    }
+    return {{ $s.Receiver }}.{{ $f.Name }}, true
+    {{- else }}
+    return {{ $s.Receiver }}.{{ $f.ConditionalField }}.Has({{ $f.ConditionalIndex }})
+    {{- end }}
+    {{- else }}
+    return {{ $s.Receiver }}.{{ $f.Name }}
+    {{- end }}
+}
+{{- end }}{{- end }}
+
+{{ end }}