Update GitHub Actions for Flutter web build and deploy

Added steps to build and deploy Flutter web application.

Author: lgund

.github/workflows/flutter-web.yml

@@ -0,0 +1,48 @@
+name: Deploy Flutter Web to GitHub Pages
+
+on:
+  push:
+    branches: [ "main" ]
+  pull_request:
+    branches: [ "main" ]
+
+permissions:
+  contents: write
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout Repository
+        uses: actions/checkout@v4
+
+      # Note: This workflow uses the latest stable version of the Dart SDK.
+      # You can specify other versions if desired, see documentation here:
+      # https://github.com/dart-lang/setup-dart/blob/main/README.md
+      # - uses: dart-lang/setup-dart@v1
+      - name: Set up Flutter
+        uses: dart-lang/setup-dart@9a04e6d73cca37bd455e0608d7e5092f881fd603
+
+      - name: Install dependencies
+        run: dart pub get
+
+      # Consider passing '--fatal-infos' for slightly stricter analysis.
+      - name: Analyze project source
+        run: dart analyze
+
+
+      - name: Build Web
+        run: flutter build web --release --base-href "/Polizei-Flutter-Template/"
+
+      # Your project will need to have tests in test/ and a dependency on
+      # package:test for this step to succeed. Note that Flutter projects will
+      # want to change this to 'flutter test'.
+      - name: Run tests
+        run: dart test
+
+      - name: Deploy to GitHub Pages
+        uses: peaceiris/actions-gh-pages@v3
+        with:
+          github_token: ${{ secrets.GITHUB_TOKEN }}
+          publish_dir: build/web