- added earliestPublicationDate for App/Models/Dataset.ts

- new classes TokenWorkerService.ts, TokenWorker.ts and ResumptionToken.ts for using REDIS with paging OAI results
- deletd public/asstes2/langCodeMap.xml: integrated it directly in datasetxml2oai-pmh.xslt
- added redis npm package
- added TokenWorkerProvider.ts for using singleton of TokenWorkerService inside OaiController.ts
- added config/oai.ts for oai related configs from .env-file
- adapted XmlModel.ts for grting domDocument from database

providers/TokenWorkerProvider.ts

@@ -0,0 +1,61 @@
+import type { ApplicationContract } from '@ioc:Adonis/Core/Application';
+
+/*
+|--------------------------------------------------------------------------
+| Provider
+|--------------------------------------------------------------------------
+|
+| Your application is not ready when this file is loaded by the framework.
+| Hence, the top level imports relying on the IoC container will not work.
+| You must import them inside the life-cycle methods defined inside
+| the provider class.
+|
+| @example:
+|
+| public async ready () {
+|   const Database = this.app.container.resolveBinding('Adonis/Lucid/Database')
+|   const Event = this.app.container.resolveBinding('Adonis/Core/Event')
+|   Event.on('db:query', Database.prettyPrint)
+| }
+|
+*/
+export default class TokenWorkerProvider {
+    public static needsApplication = true;
+    private tokenWorkerInstance; //: TokenWorkerService | null = null;
+
+    constructor(protected app: ApplicationContract) {}
+
+    public register() {
+        // Register your own bindings
+        // Bind TokenWorker to the IoC container
+        this.app.container.singleton('App/Library/Oai/TokenWorkerContract', () => {
+            // 1. import the oai configuration
+            const ttl: number = 86400;
+
+            // 2. import our REDIS wrapper class
+            const TokenWorkerService = require('App/Library/Oai/TokenWorkerSerice').default;
+            this.tokenWorkerInstance = new TokenWorkerService(ttl);
+
+            // 3. return a new instance
+            return this.tokenWorkerInstance;
+        });
+    }
+
+    // public async boot() {
+    //     // All bindings are ready, feel free to use them
+    //     // optionally do some initial setup
+    // }
+
+    // public async ready() {
+    //     // App is ready
+    // }
+
+    public async shutdown() {
+        console.log('TokenServerProvider shutdown()');
+        // Cleanup, since app is going down
+        if (this.tokenWorkerInstance) {
+            // Call the disconnect method when the application is shutting down
+            await this.tokenWorkerInstance.close();
+        }
+    }
+}