components: move ViewHeightSensor

we've moved all of the other components already

src/utils/ViewHeightSensor.test.tsx

@@ -1,11 +0,0 @@
-// SPDX-License-Identifier: MIT
-// Copyright (c) 2021 The Pybricks Authors
-
-import { render } from '@testing-library/react';
-import React from 'react';
-import ViewHeightSensor from './ViewHeightSensor';
-
-it('should set the --pb-vh variable on resize', () => {
-    render(<ViewHeightSensor />);
-    // REVISIT: it is not easy to test the resize event since jest-dom doesn't do layout
-});

src/utils/ViewHeightSensor.tsx

@@ -1,29 +0,0 @@
-// SPDX-License-Identifier: MIT
-// Copyright (c) 2022 The Pybricks Authors
-
-/* This is a hack for correctly sizing to view height on mobile when not running in fullscreen mode. */
-
-import { ResizeSensor } from '@blueprintjs/core';
-import React from 'react';
-
-/* https://css-tricks.com/the-trick-to-viewport-units-on-mobile/ */
-
-function ViewHeightSensor(): JSX.Element {
-    return (
-        <ResizeSensor
-            onResize={(e): void => {
-                document.documentElement.style.setProperty(
-                    '--pb-vh',
-                    `${e[0].contentRect.height}px`,
-                );
-            }}
-        >
-            <div
-                id="pb-vh"
-                style={{ height: '100%', width: '100%', position: 'absolute' }}
-            />
-        </ResizeSensor>
-    );
-}
-
-export default ViewHeightSensor;