Hide scroll speed changes in std and ctb editor

[OliBomby]

closes #29336

Test is broken because you cant make a DrawableRuleset of a TestBeatmap. Is there a better way to extract ruleset information from the beatmap?

[bdach]

Yeah I dunno. The conditional seems generally sane, but I'm not sure how to fix the test aside from just... fixing the test itself to not use a TestBeatmap.

The fact that instantiating a DrawableRuleset to check this worries me. I'm also acutely aware that the other rulesets will want to have SVs shown likely on both timelines, so I'm not super sure this is the correct direction in general. Maybe the thing here is to have settable or overridable flags, and override them on a per-ruleset basis rather than trying to backwards-reason the flag's value from drawable rulesets...? @ppy/team-client would like to hear thoughts

[OliBomby]

I think I found a decent solution.

To draw scroll speed changes is now determined by an overridable flag in Ruleset. This eliminates the need to instantiate a drawable ruleset entirely and removes the need for IDrawableScrollingRuleset.VisualisationMethod. It seems that interface value was only being used for determining whether to draw scroll speed in the editor timing section.

I also fixed an unrelated issue of missing scroll speed visualisation at the start of kiai sections. They were being drawn off-screen because of a wrong positioning calculation.

[smoogipoo]

I'm a bit concerned about the scope creep in polluting Ruleset, but I suppose I'm fine with this for the time being.

[bdach]

I'm a bit concerned about the scope creep in polluting Ruleset

That's why I was expecting more discussion to happen here rather than a quick merge.

I think we'll need to do a very API-breaking pass on Ruleset anyway at some point. The API is very haphazard and needs to be structured better.