Refactor package structure

Builds but not tested

pkg/archive/s3Backend.go

@@ -0,0 +1,13 @@
+// Copyright (C) 2022 NHR@FAU, University Erlangen-Nuremberg.
+// All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+package archive
+
+type S3ArchiveConfig struct {
+	Path string `json:"filePath"`
+}
+
+type S3Archive struct {
+	path string
+}