Implement timer-since-last-dot to force ghosts to leave house

[nucleartide]

Changelog

What is the "shippable increment" of this pull request?

• Add ARuntimeSet utility
• Add AGhostHouseQueue actor which inherits from ARuntimeSet
• Add FIntFieldWithLastUpdatedTime utility
• Add LeaveGhostHousePriority UPROPERTY to AGhostPawn
• Update level format so that ‘G’ is treated as a “within ghost house” tile
• Update conditions so that ghosts leave ghost house if a dot hasn’t been consumed after 5s, but in priority order
• Update per-ghost thresholds for leaving ghost house

Dev checklist

• First draft. Implement a working first pass at the feature.
• Final draft. Perform a general review of Files changed and revise anything that needs to be cleaned up.
• Debuggability. Ensure that all features within this pull request can be inspected in Unreal Editor. Most often this means slapping a UPROPERTY(VisibleAnywhere) on all data fields, but can also mean drawing debug geometry for trickier logic.
• Playtest. Playtest through game to ensure everything works.
• Merge and release. Merge into master, cut a new build in Unreal, and upload a GitHub release.

After a break

• (one time) how do i inspect fps in a running build? F3 still works
• Summary. Collect changelog items.
• Writeup. Do a CAR/STAR writeup within this pull request.
• Priorities. Prioritize items on work board.
• Next task. Tee up a pull request for the next feature.