Add missing unit test file

packages/file-handling/test/unit.js

+import '../src/vpu-kb-wpe-view';
+import '../src/demo';
+
+describe('vpu-fileupload basics', () => {
+  let node;
+
+  beforeEach(async () => {
+    node = document.createElement('vpu-fileupload');
+    document.body.appendChild(node);
+    await node.updateComplete;
+  });
+
+  afterEach(() => {
+    node.remove();
+  });
+
+  it('should render', () => {
+      expect(node).to.have.property('shadowRoot');
+  });
+});
+
+describe('vpu-fileupload demo', () => {
+  let node;
+
+  beforeEach(async () => {
+    node = document.createElement('vpu-fileupload-demo');
+    document.body.appendChild(node);
+    await node.updateComplete;
+  });
+
+  afterEach(() => {
+    node.remove();
+  });
+
+  it('should render', () => {
+      expect(node).to.have.property('shadowRoot');
+  });
+});