Core/VMAPs: Fix map object orientation

Merge https://github.com/249CAAFE40/mangos-wotlk/commit/2f8b8e55d99122d34be2a08cbdbd2d2b1ae172d1

Fixes many map object's rotation being flipped, causing LoS errors, pathing glitches, height mistakes, etc when standing near them

You will need to re-extract vmaps and re-generate mmaps for these changes to take effect.

credit to jackpoz & 249CAAFE40