Adventure: QOL improvements for "Clear All" quests

[jumpinjackie]

AI Disclosure: All code in this PR up to this point of submission was written by GitHub Copilot, based on the original issue description as the planning prompt with further refinements through additional natural language prompts. I've dabbled in Java (C#, JavaScript, TypeScript are my predominant languages), so I should be able to follow-up on any implementation feedback. I may tap into further assistance from Copilot for addressing any architectural-level concerns.

This PR improves the QoL around "Clear All" quests in Adventure Mode.

Firstly, if you are in a cave/dungeon with an active "Clear All" quest, the remaining enemy count is shown on the bottom right.

When dealing with hidden enemies, manually walking/scanning every pixel on the map to find these hidden enemies is not my (and many others) idea of fun. Showing the enemy count doesn't really help in this respect, so this PR includes an opt-in setting to draw chevrons pointing to each hidden enemy.

When this flag is active, chevrons will point to the hidden enemies.

Chevrons are never drawn for visible enemies in a "Clear All" quest.

Fixes #7845 (and many other closed-via-inactivity duplicates. This one was chosen because it was the one referenced in the Adventure Mode Subproject)

[Agetian]

Looks good for merge imo, but needs a conflict resolution in one of the files

[jumpinjackie]

Merge conflict resolved