Move sdk structs to modules/structs (#6905)

* move sdk structs to moduels/structs

* fix tests

* fix fmt

* fix swagger

* fix vendor

modules/structs/attachment.go

@@ -0,0 +1,27 @@
+// Copyright 2017 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package structs // import "code.gitea.io/gitea/modules/structs"
+import (
+	"time"
+)
+
+// Attachment a generic attachment
+// swagger:model
+type Attachment struct {
+	ID            int64  `json:"id"`
+	Name          string `json:"name"`
+	Size          int64  `json:"size"`
+	DownloadCount int64  `json:"download_count"`
+	// swagger:strfmt date-time
+	Created     time.Time `json:"created_at"`
+	UUID        string    `json:"uuid"`
+	DownloadURL string    `json:"browser_download_url"`
+}
+
+// EditAttachmentOptions options for editing attachments
+// swagger:model
+type EditAttachmentOptions struct {
+	Name string `json:"name"`
+}