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/tgerr/flood_wait.go

@@ -0,0 +1,77 @@
+package tgerr
+
+import (
+	"context"
+	"time"
+
+	"go.mau.fi/mautrix-telegram/pkg/gotd/clock"
+)
+
+// ErrPremiumFloodWait is error type of "FLOOD_PREMIUM_WAIT" error.
+const ErrPremiumFloodWait = "FLOOD_PREMIUM_WAIT"
+
+// ErrFloodWait is error type of "FLOOD_WAIT" error.
+const ErrFloodWait = "FLOOD_WAIT"
+
+// FloodWaitErrors is a list of errors that are considered as flood wait.
+var FloodWaitErrors = []string{ErrFloodWait, ErrPremiumFloodWait}
+
+// AsFloodWait returns wait duration and true boolean if err is
+// the "FLOOD_WAIT" error.
+//
+// Client should wait for that duration before issuing new requests with
+// same method.
+func AsFloodWait(err error) (d time.Duration, ok bool) {
+	for _, e := range FloodWaitErrors {
+		if rpcErr, ok := AsType(err, e); ok {
+			return time.Second * time.Duration(rpcErr.Argument), true
+		}
+	}
+	return 0, false
+}
+
+type floodWaitOptions struct {
+	clock clock.Clock
+}
+
+// FloodWaitOption configures flood wait.
+type FloodWaitOption interface {
+	apply(o *floodWaitOptions)
+}
+
+type floodWaitOptionFunc func(o *floodWaitOptions)
+
+func (f floodWaitOptionFunc) apply(o *floodWaitOptions) {
+	f(o)
+}
+
+// FloodWaitWithClock sets time source for flood wait.
+func FloodWaitWithClock(c clock.Clock) FloodWaitOption {
+	return floodWaitOptionFunc(func(o *floodWaitOptions) {
+		o.clock = c
+	})
+}
+
+// FloodWait sleeps required duration and returns true if err is FLOOD_WAIT
+// or false and context or original error otherwise.
+func FloodWait(ctx context.Context, err error, opts ...FloodWaitOption) (bool, error) {
+	opt := &floodWaitOptions{
+		clock: clock.System,
+	}
+	for _, o := range opts {
+		o.apply(opt)
+	}
+	if d, ok := AsFloodWait(err); ok {
+		timer := opt.clock.Timer(d + 1*time.Second)
+		defer clock.StopTimer(timer)
+
+		select {
+		case <-timer.C():
+			return true, err
+		case <-ctx.Done():
+			return false, ctx.Err()
+		}
+	}
+
+	return false, err
+}