Add unicode scanner to github workflows.

Author: fisx

.github/workflows/unicode-scan.yaml

@@ -0,0 +1,13 @@
+name: Unicode Security Scan
+
+on: [push, pull_request]
+
+jobs:
+  scan:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - name: Scan for Trojan Source
+        uses: nickboucher/trojan-source-scanner@v1
+        with:
+          fail-on-detection: true