GatherHud TBC

## v1.2.0
Not the original author - this update only fixes broken API calls and adds
a few new options on top of the original addon by Grum and Xinhuan.

Updated for Burning Crusade Classic Anniversary patch 2.5.6 (Interface 20506).

API fixes (previously broken/non-functional on current client):
- Fixed LoadAddOn (removed global) -> C_AddOns.LoadAddOn
- Fixed player position tracking: GetPlayerMapPosition/GetCurrentMapAreaID/
  GetCurrentMapDungeonLevel (all removed by Blizzard) -> C_Map API
- Fixed zone size lookup: GatherMate:GetZoneSize -> GatherMate.HBD:GetZoneSize
  (GatherMate2 now uses the HereBeDragons library internally)
- Fixed FindNearbyNode call to match GatherMate2's current parameter order
  (the old "dungeon level" parameter no longer exists)
- Fixed pin coordinate decoding: GatherMate.mapData:DecodeLoc -> GatherMate:DecodeLoc
- Fixed a crash when enabling "Use Character Pitch" (GetUnitPitch was removed
  by Blizzard in patch 7.1 and will never return); now fails gracefully and
  falls back to the manual angle-of-view setting

New features:
- New "North Up" option: keeps the hud oriented with North always up instead
  of rotating with your character
- New "Direction Arrow" option: replaces the player dot with a rotating arrow
  showing your current facing (most useful together with North Up)
- New independent "Player Icon Size" slider, no longer tied to resource icon size
- New "Highlight likely-present resources" option: resource icons turn yellow
  and enlarge when the matching tracking (Find Herbs/Find Minerals) is active
  and you're within detection range - similar to the native minimap dot.
  This is a proximity/tracking-state estimate (the same one GatherMate2 itself
  uses for its own minimap pins), not a guaranteed live confirmation - Blizzard
  does not expose that to addons.
- Player icon now always renders above resource pins (fixed a layering issue
  where resource icons could cover it)