Core/MovementHandler: Make it possible to get exact player position from m_movementInfo in some cases

[r4d1sh]

Changes proposed:

The problem is that upon player landing, we call Player::HandleFall and Unit::RemoveAurasWithInterruptFlags before updating Player::m_movementInfo and before calling Unit::UpdatePosition.

This leads to a situation where if we're writing a PlayerScript and hook player death from falling, or writing an AuraScript and hook aura removal (parachute) then within the same server tick, we won't be able to get the exact position where the player landed.

In this PR, I've changed the call order in WorldSession::HandleMovementOpcodes so that the order of packets sent to client remains the same. But now we can get the exact position of the player (player->m_movementInfo.pos) at the moment of landing.

Tests performed:

Builded and tested in-game.