frontend: Move updating the UI on marking read to after fetch return.
frontend: Move updating the UI on marking read to after fetch return.

This prevents a race if the page is navigated around quickly after marking things as read before the backend is done, leading to inconsistent UI state.

jrupac/goliath,jrupac/goliath,jrupac/goliath,jrupac/goliath,jrupac/goliath