[Layout] Add ul support to Box (#7803)

### WHY are these changes introduced?

Supports #7458

### WHAT is this pull request doing?

`Box` can now be rendered as a `ul` with reset styles

Author: aveline

.changeset/happy-llamas-doubt.md

@@ -0,0 +1,6 @@
+---
+'@shopify/polaris': minor
+'polaris.shopify.com': patch
+---
+
+Added support for `ul` element on `Box`

polaris-react/src/components/Box/Box.scss

@@ -112,3 +112,11 @@
 .visuallyHidden {
   @include visually-hidden;
 }
+
+.listReset {
+  list-style-type: none;
+  margin-block-start: 0;
+  margin-block-end: 0;
+  outline: none;
+  padding-inline-start: 0;
+}

polaris-react/src/components/Box/Box.tsx

@@ -19,7 +19,7 @@ import {
 
 import styles from './Box.scss';
 
-type Element = 'div' | 'span' | 'section';
+type Element = 'div' | 'span' | 'section' | 'ul';
 type Overflow = 'hidden' | 'scroll';
 type Position = 'relative' | 'absolute' | 'fixed' | 'sticky';
 
@@ -321,6 +321,7 @@ export const Box = forwardRef<HTMLElement, BoxProps>(
     const className = classNames(
       styles.Box,
       visuallyHidden && styles.visuallyHidden,
+      as === 'ul' && styles.listReset,
     );
 
     return createElement(