- 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

app/Library/Oai/ResumptionToken.ts

@@ -0,0 +1,51 @@
+export default class ResumptionToken {
+    private _documentIds: number[] = [];
+    private _metadataPrefix = '';
+    private _resumptionId = '';
+    private _startPosition = 0;
+    private _totalIds = 0;
+
+    get key(): string {
+        return this.metadataPrefix + this.startPosition + this.totalIds;
+    }
+
+    get documentIds(): number[] {
+        return this._documentIds;
+    }
+
+    set documentIds(idsToStore: number | number[]) {
+        this._documentIds = Array.isArray(idsToStore) ? idsToStore : [idsToStore];
+    }
+
+    get metadataPrefix(): string {
+        return this._metadataPrefix;
+    }
+
+    set metadataPrefix(value: string) {
+        this._metadataPrefix = value;
+    }
+
+    get resumptionId(): string {
+        return this._resumptionId;
+    }
+
+    set resumptionId(resumptionId: string) {
+        this._resumptionId = resumptionId;
+    }
+
+    get startPosition(): number {
+        return this._startPosition;
+    }
+
+    set startPosition(startPosition: number) {
+        this._startPosition = startPosition;
+    }
+
+    get totalIds(): number {
+        return this._totalIds;
+    }
+
+    set totalIds(totalIds: number) {
+        this._totalIds = totalIds;
+    }
+}