Core/Units: flight and hover checks will now consider movement template data as well as manually set flight states

- manually set flight states via auras and scripts will no longer be ignored
- restored movement template consideration when generating pathings
- renamed IsLevitating to IsGravityDisabled to reflect the referenced movement flag's name

src/server/game/Entities/Unit/Unit.cpp

@@ -13090,7 +13090,7 @@ bool Unit::SetWalk(bool enable)
 
 bool Unit::SetDisableGravity(bool disable, bool /*packetOnly = false*/)
 {
-    if (disable == IsLevitating())
+    if (disable == IsGravityDisabled())
         return false;
 
     if (disable)