Don't include nested hit objects' `DifficultyControLPoints` in legacy encoder logic
Don't include nested hit objects' `DifficultyControLPoints` in legacy encoder logic

The editor doesn't currently propagate velocity to nested objects. We're
not yet sure whether it should or not. For now, let's just ignore nested
objects' `DifficultyControlPoints` for simplicity.

Note that this only affects osu! ruleset due to the pre-check on
`isOsuRuleset`.

peppy/osu,ppy/osu,NeoAdonis/osu,NeoAdonis/osu,ppy/osu,peppy/osu,peppy/osu,NeoAdonis/osu,ppy/osu