Fix socket icons not following character-sheet equipment order

[dfrisone]

What does this PR do?

Fixes Stickybackpack's report that character-sheet socket icons appear in a different order from the equipment slots. The strip previously followed inventory slot IDs, putting waist/legs/feet before wrists/hands and the back slot after trinkets.

Orders the same 16 supported slots down the left column, down the right column, then weapons: head, neck, shoulders, back, chest, wrists, hands, waist, legs, feet, rings, trinkets, main hand, off hand. Items without sockets are skipped and sockets within an item retain their socket-index order.

This is a separate ordering correction from #2109 (overflow paging), with no dependency on that PR.

How was it tested?

• Reviewed against Blizzard's character-sheet slot anchors in PaperDollFrame.xml.
• Verified the slot list retains exactly the same 16 unique IDs; the only consumer scans them with ipairs and preserves the real equipment slot/socket index on each record.
• Complete runtime file compiles under Lua 5.1. EUI style gate and git diff --check pass. No locale strings changed.
• Review found no issues requiring changes: one file, no public API or SavedVariables changes, new events/hooks, allocations, or additional runtime work.
• A reporter test ZIP combines this ordering correction with Fix character-sheet socket strip overflowing with many gems #2109. In-game confirmation of the new order is pending; no client build is recorded. Earlier paging validation does not establish ordering validation.

Screenshots

Before/after screenshots for this ordering change are missing.

Checklist

• New settings default OFF (no behavior change without opt-in) - N/A: no new setting; corrects the socket strip's equipment order.
• Zero cost while disabled: no events registered, no polling, no hooks doing work, no frames built - only reorders existing constants; no added work.
• Cheap while enabled: event-driven (no polling, no timer-based logic, no per-frame allocations) - same existing scan over 16 slots.
• No writes onto Blizzard-owned frames (weak-table pattern used); HookScript/hooksecurefunc only, never SetScript on Blizzard frames - N/A: no frame writes or hooks changed.
• Tested in-game on live; no version gates or pre-Midnight APIs added - in-game ordering verification pending. No APIs or version gates added; Midnight 12.1+ scope retained.