added admin settings service and api; made filesystem paths configurable; added babel config; added admin settings webpack config

lib/Controller/AdminSettingsController.php

@@ -0,0 +1,47 @@
+<?php
+
+namespace OCA\GroupfolderFilesystemSnapshots\Controller;
+
+use OCP\AppFramework\Controller;
+use OCP\AppFramework\Http\JSONResponse;
+use OCP\IRequest;
+
+use OCA\GroupfolderFilesystemSnapshots\AppInfo\Application;
+use OCA\GroupfolderFilesystemSnapshots\Service\SettingsService;
+
+class AdminSettingsController extends Controller {
+	public function __construct(
+		private SettingsService $settingsService,
+	) {
+		parent::__construct(
+			Application::APP_ID,
+			\OC::$server->get(IRequest::class),
+		);
+	}
+
+    /**
+     * @return JSONResponse
+     */
+    public function index(): JSONResponse {
+        return new JSONResponse($this->settingsService->getAppValues());
+    }
+
+    /**
+     * @param $key
+     *
+     * @return JSONResponse
+     */
+    public function show($key): JSONResponse {
+        return new JSONResponse($this->settingsService->getAppValue($key));
+    }
+
+    /**
+     * @param $key
+     * @param $value
+     *
+     * @return JSONResponse
+     */
+    public function update($key, $value): JSONResponse {
+		return new JSONResponse($this->settingsService->setAppValue($key, $value));
+    }
+}