fix(connector-xdai): add missing hasTransactionFinality

This was overlooked by GitHub's auto-rebase of the PR
that introduced this issue so hot-fixing this
ASAP in order to stop blocking every single new PR from running the CI
suite correctly.

Signed-off-by: Peter Somogyvari <peter.somogyvari@accenture.com>

packages/cactus-plugin-ledger-connector-xdai/src/main/typescript/plugin-ledger-connector-xdai.ts

@@ -21,6 +21,7 @@ import {
   IPluginKeychain,
 } from "@hyperledger/cactus-core-api";
 
+import { consensusHasTransactionFinality } from "@hyperledger/cactus-core";
 import { PluginRegistry } from "@hyperledger/cactus-core";
 
 import {
@@ -122,6 +123,11 @@ export class PluginLedgerConnectorXdai
     this.prometheusExporter.startMetricsCollection();
   }
 
+  public async hasTransactionFinality(): Promise<boolean> {
+    const consensusAlgorithmFamily = await this.getConsensusAlgorithmFamily();
+    return consensusHasTransactionFinality(consensusAlgorithmFamily);
+  }
+
   public getPrometheusExporter(): PrometheusExporter {
     return this.prometheusExporter;
   }