QoL: Current Expansion Only for AH and crafting orders

[liamcooper]

Summary

• Adds a single Current Expansion Only QoL toggle (ahCurrentExpansion) for both Auction House browse and Place Crafting Order.
• Moves logic into EllesmereUIQoL_ExpansionFilters.lua with secure hooksecurefunc hooks; setup events unregister after Blizzard addons are hooked.
• AH applies the filter after Blizzard resets search bars on show; crafting orders apply on open and respect manual uncheck until the window is reopened.

Test plan

• Enable Current Expansion Only in QoL, /reload
• Open Auction House browse — filter is on; switching tabs still applies after Blizzard reset
• Open Place Crafting Order — filter is on at open (favorites list unchanged; expansion applies on Search)
• Uncheck expansion in Filter menu — stays off until window is closed and reopened
• Disable toggle — no filter applied on AH or crafting orders