Add list duplicate (#172)

Add list duplicate

Co-authored-by: kolaente <k@knt.li>
Reviewed-on: https://kolaente.dev/vikunja/frontend/pulls/172

src/services/listDuplicateService.js

@@ -0,0 +1,20 @@
+import AbstractService from './abstractService'
+import listDuplicateModel from '../models/listDuplicateModel'
+
+export default class ListDuplicateService extends AbstractService {
+	constructor() {
+		super({
+			create: '/lists/{listId}/duplicate',
+		})
+	}
+
+	beforeCreate(model) {
+
+		model.list = null
+		return model
+	}
+
+	modelFactory(data) {
+		return new listDuplicateModel(data)
+	}
+}