[bugfix] Normalize status content (don't parse status content as IRI) (#1665)

* start fannying about

* finish up Normalize

* tidy up

* pin to tag

* move errors about just a little bit

internal/ap/error.go

@@ -0,0 +1,35 @@
+// GoToSocial
+// Copyright (C) GoToSocial Authors admin@gotosocial.org
+// SPDX-License-Identifier: AGPL-3.0-or-later
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package ap
+
+import "fmt"
+
+// ErrWrongType indicates that we tried to resolve a type into
+// an interface that it's not compatible with, eg a Person into
+// a Statusable.
+type ErrWrongType struct {
+	wrapped error
+}
+
+func (err *ErrWrongType) Error() string {
+	return fmt.Sprintf("wrong received type: %v", err.wrapped)
+}
+
+func newErrWrongType(err error) error {
+	return &ErrWrongType{wrapped: err}
+}