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/uploader/source/http.go

@@ -0,0 +1,82 @@
+package source
+
+import (
+	"context"
+	"io"
+	"net/http"
+	"net/url"
+	"path"
+
+	"github.com/go-faster/errors"
+	"go.uber.org/multierr"
+)
+
+// HTTPSource is HTTP source.
+type HTTPSource struct {
+	client *http.Client
+}
+
+// NewHTTPSource creates new HTTPSource.
+func NewHTTPSource() *HTTPSource {
+	return &HTTPSource{client: http.DefaultClient}
+}
+
+// WithClient sets HTTP client to use.
+func (s *HTTPSource) WithClient(client *http.Client) *HTTPSource {
+	s.client = client
+	return s
+}
+
+type httpFile struct {
+	body io.ReadCloser
+	name string
+	size int64
+}
+
+func (h httpFile) Read(p []byte) (n int, err error) {
+	return h.body.Read(p)
+}
+
+func (h httpFile) Close() error {
+	return h.body.Close()
+}
+
+func (h httpFile) Name() string {
+	return h.name
+}
+
+func (h httpFile) Size() int64 {
+	return h.size
+}
+
+// Open implements Source.
+func (s *HTTPSource) Open(ctx context.Context, u *url.URL) (_ RemoteFile, rerr error) {
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, u.String(), nil)
+	if err != nil {
+		return nil, errors.Wrap(err, "create request")
+	}
+
+	resp, err := s.client.Do(req)
+	if err != nil {
+		return nil, errors.Wrap(err, "get")
+	}
+	defer func() {
+		if rerr != nil {
+			multierr.AppendInto(&rerr, resp.Body.Close())
+		}
+	}()
+	if resp.StatusCode >= 400 {
+		return nil, errors.Errorf("bad code %d", resp.StatusCode)
+	}
+
+	lastURL := u
+	if resp.Request.URL != nil {
+		lastURL = resp.Request.URL
+	}
+
+	return httpFile{
+		body: resp.Body,
+		name: path.Base(lastURL.Path),
+		size: resp.ContentLength,
+	}, nil
+}