Fix Simplified Rhythm mod breaking diffcalc when applied to some maps

[bdach]

• closes Simplified Rhythm (1/3 to 1/2 conversion) breaks certain taiko beatmaps #36942
• fixes https://osu.ppy.sh/community/forums/topics/2187041?n=1

Ensure Simplified Rhythm mod does not produce beatmaps with objects out of order

This is a last ditch safety.

This mod has more apparent issues (see below) but this is a first step of restoring sanity.

Aside than the other fix described below I have not attempted to figure out further why this is happening because the conversion logic is in over my head. I just want hard breakage to not be possible. Why this extra sort is necessary can be investigated by @Hiviexd if he's so inclined.

Fix GetClosestBeatDivisor() not working correctly with negative time instants

This was causing the 1/3 -> 1/2 conversion in Simplified Rhythm to engage on some maps that weren't even mapped in waltz time. Those maps had the common trait of having a timing point with a negative start time.

Notably this could feasibly affect other places as well, like mania beat snap colouring, or the Synesthesia osu! mod.

testing

Tested with Simplified Rhythm engaged, with 1/6 -> 1/4 and 1/3 -> 1/2 conversion enabled

BULANOVA - NE PLACH' [oni] (1/8 snap):

• No mods: 5.18*
• Simplified Rhythm @ master: 0.00*
• Simplified Rhythm @ f4807b3: 3.48*
• Simplified Rhythm @ 933de7a: 5.18*

BULANOVA - NE PLACH' [inner oni] (1/8 snap):

• No mods: 5.84*
• Simplified Rhythm @ master: 0.00*
• Simplified Rhythm @ f4807b3: 4.13*
• Simplified Rhythm @ 933de7a: 5.84*

BULANOVA - NE PLACH' [don't cry] (1/8 snap):

• No mods: 6.91*
• Simplified Rhythm @ master: 0.00*
• Simplified Rhythm @ f4807b3: 4.84*
• Simplified Rhythm @ 933de7a: 6.91*

Mili - Peach Pit and Cyanide [nik's Normal] (1/6 snap):

• No mods: 1.63*
• Simplified Rhythm @ master: 0.00*
• Simplified Rhythm @ f4807b3: 1.10*
• Simplified Rhythm @ 933de7a: 1.10*

Mili - Peach Pit and Cyanide [Ix's Hard] (1/3 snap):

• No mods: 2.50*
• Simplified Rhythm @ master: 0.00*
• Simplified Rhythm @ f4807b3: 1.71*
• Simplified Rhythm @ 933de7a: 1.71*

Mili - Peach Pit and Cyanide [nomi's Hidden Insane] (1/3 snap):

• No mods: 3.93*
• Simplified Rhythm @ master: 0.00*
• Simplified Rhythm @ f4807b3: 2.59*
• Simplified Rhythm @ 933de7a: 2.59*

Within Temptation - The Unforgiving [Stairway To The Skies] (1/3 snap in editor):

• No mods: 1.53*
• Simplified Rhythm @ master: 0.00*
• Simplified Rhythm @ f4807b3: 1.48*
• Simplified Rhythm @ 933de7a: 1.48*

Within Temptation - The Unforgiving [Iron] (1/6 snap in editor):

• No mods: 2.76*
• Simplified Rhythm @ master: 0.00*
• Simplified Rhythm @ f4807b3: 1.75*
• Simplified Rhythm @ 933de7a: 1.75*

Within Temptation - The Unforgiving [Marathon] (1/4 snap in editor, but has 1/3 / 1/6 sections for sure):

• No mods: 2.96*
• Simplified Rhythm @ master: 0.00*
• Simplified Rhythm @ f4807b3: 2.75*
• Simplified Rhythm @ 933de7a: 2.75*

Halozy - Genryuu Kaiko [Higan Torrent] (1/4 snap):

• No mods: 5.37*
• Simplified Rhythm @ master: 0.00*
• Simplified Rhythm @ f4807b3: 3.95*
• Simplified Rhythm @ 933de7a: 5.37*