[bugfix] internal server error on search not found (#1590)

* add error value wrapping, include status code / not found flags from transport errors, update error usages

Signed-off-by: kim <grufwub@gmail.com>

* add code commenting for gtserror functions

Signed-off-by: kim <grufwub@gmail.com>

---------

Signed-off-by: kim <grufwub@gmail.com>

internal/transport/dereference.go

@@ -20,7 +20,6 @@ package transport
 
 import (
 	"context"
-	"errors"
 	"fmt"
 	"io"
 	"net/http"
@@ -28,15 +27,10 @@ import (
 
 	apiutil "github.com/superseriousbusiness/gotosocial/internal/api/util"
 	"github.com/superseriousbusiness/gotosocial/internal/config"
+	"github.com/superseriousbusiness/gotosocial/internal/gtserror"
 	"github.com/superseriousbusiness/gotosocial/internal/uris"
 )
 
-// ErrGone is returned from Dereference when the remote resource returns 410 GONE.
-// This is useful in cases where we're processing a delete of a resource that's already
-// been removed from the remote server, so we know we don't need to keep trying to
-// dereference it.
-var ErrGone = errors.New("remote resource returned HTTP code 410 GONE")
-
 func (t *transport) Dereference(ctx context.Context, iri *url.URL) ([]byte, error) {
 	// if the request is to us, we can shortcut for certain URIs rather than going through
 	// the normal request flow, thereby saving time and energy
@@ -72,12 +66,10 @@ func (t *transport) Dereference(ctx context.Context, iri *url.URL) ([]byte, erro
 	}
 	defer rsp.Body.Close()
 
-	switch rsp.StatusCode {
-	case http.StatusOK:
-		return io.ReadAll(rsp.Body)
-	case http.StatusGone:
-		return nil, ErrGone
-	default:
-		return nil, fmt.Errorf("GET request to %s failed: %s", iriStr, rsp.Status)
+	if rsp.StatusCode != http.StatusOK {
+		err := fmt.Errorf("GET request to %s failed: %s", iriStr, rsp.Status)
+		return nil, gtserror.WithStatusCode(err, rsp.StatusCode)
 	}
+
+	return io.ReadAll(rsp.Body)
 }