Add remember_state prop to accordion

Problem/Motivation

For e.g. an accordion that spans multiple pages (such as an FAQ in the footer region) it may be useful for the expanded/collapsed state of accordions to persist across page loads for a given user.

Steps to reproduce

Load a page with an accordion
Collapse (or expand) accordion items
Refresh the page
Confirm they are still expanded/collapsed if appropriate

Proposed resolution

Add e.g. remember_state prop to accordion. If true, state will persist using browser's localStorage (so state only applies to current visitor)