[ci/cueweb/rest_gateway] Add Docker build jobs for cueweb and rest_gateway (#2098)

**Link the Issue(s) this Pull Request is related to.**
- #2053

**Summarize your change.**

[ci/cueweb/rest_gateway] Add Docker build jobs for CueWeb and OpenCue
REST Gateway

Add CI/CD jobs to the testing pipeline to build Docker images for CueWeb
and OpenCue REST Gateway components. This ensures the Docker build
workflow is validated on every push and PR to master.

New jobs:
- build_cueweb: Builds the Next.js web interface Docker image
- build_rest_gateway: Builds the Go REST gateway Docker image

Also fixes CueWeb build by adding missing @radix-ui/react-tooltip
dependency to package.json.

Author: ramonfigueiredo

.github/workflows/testing-pipeline.yml

@@ -391,3 +391,46 @@ jobs:
         with:
           name: rest-gateway-coverage
           path: rest_gateway/opencue_gateway/coverage.out
+
+  build_cueweb:
+    name: Build CueWeb Docker Image
+    runs-on: ubuntu-22.04
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+          fetch-tags: true
+
+      - name: Mark repository as safe
+        run: git config --global --add safe.directory $GITHUB_WORKSPACE
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Build CueWeb Docker image
+        working-directory: cueweb
+        run: |
+          docker buildx build . -f Dockerfile -t opencue/cueweb:test --load
+          echo "CueWeb Docker image built successfully"
+
+  build_rest_gateway:
+    name: Build REST Gateway Docker Image
+    runs-on: ubuntu-22.04
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+          fetch-tags: true
+
+      - name: Mark repository as safe
+        run: git config --global --add safe.directory $GITHUB_WORKSPACE
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Build REST Gateway Docker image
+        run: |
+          docker buildx build . -f rest_gateway/Dockerfile -t opencue/rest-gateway:test --load
+          echo "REST Gateway Docker image built successfully"