We use `export default` begrudgingly here. Ideally we'd use just `export`, though this entire SDK expects things to be exported as a default. Instead of breaking everything, we'll sacrifice our export pattern for a smaller diff - a later commit can always do the default export -> regular export conversion.
This allows Webpack to insert the proper image URL after builds steps like
adding a hash and so on. The path you supply to `require` is relative to the JS
source file, just like any other would be.
Fixes https://github.com/vector-im/riot-web/issues/6081 by making
the accept/reject buttons AccessibleButtons which they should be
anyway (presumably the role=button makes chrome do the right thing
with the events). Also swallow the onClick event otherwise that
propagates out to the room header and causes it to expand/collapse.
