orders: add search overlay for manager orders

[pajawojciech]

Add search to manager orders

Adds search box to find orders by job name + arrow indicators to show which one you're looking at.

What it does

• Search box appears on orders screen (Alt+S to focus)
• Type keywords to filter (e.g. "iron picks" finds "forge iron picks")
• Multi-word search works in any order ("picks iron" also matches)
• Alt+P/N to jump between matches
• Shows "3 of 12" style counter
• Green >> arrows point at current match
• Arrows hide when you scroll manually

Implementation

• Uses stockflow reaction names for search (see Fix user-friendly job names so that they are the same as in the manager menu scripts#1524 for upcoming names update to match in-game text)
• Two overlays: OrdersSearchOverlay for search UI, OrderHighlightOverlay for arrows
• Both disabled by default until stockflow names are updated to match in-game text
• Moved importexport overlay position to make room for search - users with saved overlay settings need to run: overlay position orders.importexport default

What didn't work

• Tried to clear search input when exiting orders window - couldn't find reliable way to detect window exit

Related issues

• Feature request: searchable Work Orders #1910
• [suggestion] add search and further sort functionality to the Work Order interface #3346

order-search.mp4