Summary

• Adds an Icons Per Row slider (range 1–40, default 40) to every bar type: Essential, Utility, Buffs, Custom, Additional Custom, Item, Trinket, and Items/Spells.
• When set below 40, icons wrap into a grid layout with multiple rows/columns (depending on growth direction).
• Default of 40 preserves existing single-row behavior — users slide left to reduce icons per row.
• Extracts duplicated layout logic from 5 custom bar modules into a shared BCDM:LayoutIconGrid() utility function, reducing ~380 lines of repeated code to ~80 lines of shared logic.
• Blizzard bars (Essential, Utility, Buffs) override iconLimit via CenterWrappedRows when the setting is active.

Changes

Test plan

• Set "Icons Per Row" to 3 on any custom bar with 6+ spells — should display 2 rows of 3
• Test each growth direction (Right, Left, Up, Down) with multi-row layout
• Set to 40 (default) — should behave identically to before this change (single row)
• Set "Icons Per Row" on Essential/Utility bars — icons should wrap at that limit
• Set "Icons Per Row" on Buffs bar — buff icons should wrap at that limit
• Verify centered layout (TOP/BOTTOM anchor + horizontal growth) centers each row independently
• Test with 1 icon per row (vertical stack)