Until now, many online textures were retrieved via the default texture store, which causes them to never be removed from GPU memory. It also has a performance overhead due to mipmap generation (which will be avoided via ppy/osu-framework#1885.
Alternative to / closes#2549.
Didn't want to reference the toolbar as was done, also wanted to remove the awkward scaling factors so rather than scaling down the inner one, we scale up the outer one.