Add action for detecting code duplicates

Signed-off-by: Szymon Kłos <szymon.klos@collabora.com>
Change-Id: I8a601aed33fbdc5654cd2e59f42307161e04e18b

.github/workflows/code-duplication.yml

@@ -0,0 +1,16 @@
+on: [pull_request]
+
+jobs:
+  dry-code-action:
+    runs-on: ubuntu-latest
+    name: Dry Code Action
+    steps:
+      - name: Checkout Repository
+        uses: actions/checkout@v2
+      - name: Dry Code Action
+        uses: Pposong-Hantaihe/dry-code@v1.0.2
+        with:
+          token: "${{ secrets.GITHUB_TOKEN }}"
+          arguments: "./browser/src"
+          options: "--min-lines=26"
+