feat: implement organization secret creation API (#26566)

- Add a new `CreateSecretOption` struct for creating secrets
- Implement a `CreateOrgSecret` function to create a secret in an
organization
- Add a new route in `api.go` to handle the creation of organization
secrets
- Update the Swagger template to include the new `CreateOrgSecret` API
endpoint

---------

Signed-off-by: appleboy <appleboy.tw@gmail.com>

services/convert/secret.go

@@ -0,0 +1,18 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package convert
+
+import (
+	secret_model "code.gitea.io/gitea/models/secret"
+	api "code.gitea.io/gitea/modules/structs"
+)
+
+// ToSecret converts Secret to API format
+func ToSecret(secret *secret_model.Secret) *api.Secret {
+	result := &api.Secret{
+		Name: secret.Name,
+	}
+
+	return result
+}