Refactor <TimePicker> to function component (#24348)

* Refactor tests to use RTL

* Add test for ordering of the month/day input

* Add storybook for <TimePicker>

* Refactor <TimePicker>

* Coding style updates as per suggested in code reviews

packages/components/src/date-time/stories/time.js

@@ -0,0 +1,26 @@
+/**
+ * Internal dependencies
+ */
+import TimePicker from '../time';
+
+/**
+ * External dependencies
+ */
+import { date, boolean } from '@storybook/addon-knobs';
+import { noop } from 'lodash';
+
+export default { title: 'Components/TimePicker', component: TimePicker };
+
+export const _default = () => {
+	return (
+		<TimePicker
+			currentTime={
+				new Date(
+					date( 'currentTime', new Date( '1986-10-18T11:00:00' ) )
+				)
+			}
+			is12Hour={ boolean( 'is12Hour', false ) }
+			onChange={ noop }
+		/>
+	);
+};