perf: Chart control performance improvements

[PaulAndersonS]

Root Cause of the Issue

Multiple hot paths in the Chart control allocate unnecessary temporary collections (via LINQ .Reverse(), .Where().ToList(), .Values.ToList(), LINQ query syntax) and perform redundant scans (multiple .Min()/.Max() calls) on every frame or data update.

Description of Change

This PR implements 8 performance improvements targeting allocation reduction and redundant computation elimination in the Chart control:

#	Improvement	Impact	File
1	Replace LINQ .Reverse() with backward for loop	HIGH	SfCartesianChart.cs
2	Replace .Where().ToList() with direct iteration	HIGH	CartesianChartArea.cs
3	(Already optimized in codebase)	—	—
4	Cache .Values.ToList() outside loops	MEDIUM	CartesianChartArea.cs
5	(PathF lacks Clear() - not feasible)	—	—
6	Cache yPropertyAccessor.Count in data binding loops	MEDIUM	ChartSeriesPartial.cs
7	Replace LINQ query syntax with pre-sized List<double> loops	MEDIUM	CartesianSeries.cs
8	Remove .Where().ToList() allocation in UpdateSbsSeries	MEDIUM	CartesianSeries.cs
9	Cache StrokeDashArray.ToFloatArray() result per segment	MEDIUM	AreaSegment.cs
10	Replace multiple LINQ .Min()/.Max()/.Where() scans with single loop	MEDIUM	AreaSegment.cs

Key benefits:

• Eliminates per-frame allocations from LINQ .Reverse() and .ToList() in hit-testing and rendering paths
• Removes redundant list materialization in side-by-side series calculation loops
• Caches dash pattern array conversion to avoid per-frame allocation
• Reduces SetData from 5+ collection scans to a single pass

Issues Fixed

Performance improvement - no specific issue

Screenshots

N/A - performance-only changes with no visual impact