Core/Maps: Fix Spline triggered assert

Fix an assert triggered by float to int32 cast overflowing to -1, now it replaces -1 with max int32 value.
Fix another assert triggered by Vector3 magnitude float overflow to max/infinity in StaticMapTree::isInLineOfSight(), in this case return false.

Both asserts can be reproduced by casting Mind Control to a NPC, tele to z: 1.0e+38 using client hack tools, move to allow the server to register the new position and stop Mind Control.

Closes #8970
Closes #10578
Closes #10355
Closes #10673