Redesign widget pip and move into shared component (#32654)

* redesign widget pip and move into shared component

* fix onBackClick handler

* fix ci

* Update README.md prepare -> prepack

* add vm tests

* Update WidgetPipView.stories.tsx

* fix tests

* playwright tests

* fix test id

* remove unused files (reappeared after rebase)

* update storybook screenshot tests

* update playwright tests

* adjust padding

* review

* comment and docstring corrections

* fix imports and `this.props`

* fix double `complementary` item

* add WidgetPipView tests and revmoe `setViewingRoom` from
WidgetPipViewModelInterface.

* add doc sting to `setViewingRoom`

* Update RoomStatusBarView.test.tsx

* fix copyright

* Update RoomView-test.tsx.snap

* revert accidental Copyright year changes

* update snapshot RoomView-test

apps/web/playwright/e2e/widgets/widget-pip-close.spec.ts

@@ -139,7 +139,7 @@ test.describe("Widget PIP", () => {
             );
 
             // checks that pip window is opened
-            await expect(page.locator(".mx_WidgetPip")).toBeVisible();
+            await expect(page.getByTestId("widget-pip-container")).toBeVisible();
 
             // checks that widget is opened in pip
             const iframe = page.frameLocator(`iframe[title="${DEMO_WIDGET_NAME}"]`);
@@ -155,7 +155,7 @@ test.describe("Widget PIP", () => {
             }
 
             // checks that pip window is closed
-            await expect(iframe.locator(".mx_WidgetPip")).not.toBeVisible();
+            await expect(iframe.getByTestId("widget-pip-container")).not.toBeVisible();
         });
     }
 });