Use `<use />` to render transparent SVG logo instead of inserting it (#10845)

app/helpers/stream_entries_helper.rb

app/javascript/images/logo_transparent.svg

app/javascript/styles/mastodon-light/diff.scss

app/javascript/styles/mastodon/containers.scss

app/javascript/styles/mastodon/footer.scss

app/javascript/styles/mastodon/stream_entries.scss

app/views/layouts/application.html.haml

app/views/layouts/public.html.haml