Allow scroll type to be specified
Allow scroll type to be specified

This brings back the ability for the carousel to scroll in a classic
way. It turns out this is generally what we want for "seek" operations
like "random", else it's quite hard to get the expected animation.

I did experiment with applying the animation after the pooled panels are
retrieved, but in a best-case scenario there is still a gap where no
panels are displayed during the random seek operation.

peppy/osu,UselessToucan/osu,smoogipoo/osu,peppy/osu-new,UselessToucan/osu,ppy/osu,ppy/osu,peppy/osu,UselessToucan/osu,NeoAdonis/osu,NeoAdonis/osu,smoogipoo/osu,peppy/osu,smoogipoo/osu,smoogipooo/osu,NeoAdonis/osu,ppy/osu