feat: Add a unit test target (jest) to the UI extension and run it in CI (#1192)

- Introduce test targets.
- Adding additional tests.

Related to: https://github.com/harvester/harvester/issues/11892

Signed-off-by: Volker Theile <vtheile@suse.com>

.github/actions/test/action.yaml

@@ -0,0 +1,12 @@
+name: Run Unit Tests
+description: Run Unit Tests
+
+runs:
+  using: 'composite'
+  steps:
+    - name: Setup env
+      uses: ./.github/actions/setup
+
+    - name: Run unit tests
+      shell: bash
+      run: yarn test:ci