Add action for translation messages

.github/workflows/test.yml

@@ -69,3 +69,30 @@ jobs:
       - name: Run jest
         run: |
           npm run test
+
+  translation-messages:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Cache node modules
+        uses: actions/cache@v2
+        env:
+          cache-name: cache-node-modules
+        with:
+          # npm cache files are stored in `~/.npm` on Linux/macOS
+          path: ~/.npm
+          key: ${{ runner.os }}-qa-${{ env.cache-name }}-${{ hashFiles('**/package-lock.json') }}
+          restore-keys: |
+            ${{ runner.os }}-qa-${{ env.cache-name }}-
+            ${{ runner.os }}-qa-
+            ${{ runner.os }}-
+
+      - name: Install deps
+        run: |
+          npm ci
+
+      - name: Check message extraction
+        run: |
+          npm run extract-messages
+          git diff ./locale