Stabilise MoveToWorld (#4004)

* Stabilise MoveToWorld

* Fix comments and deprecate ScheduleMoveToWorld

* Enhanced thread safety for m_WorldChangeInfo

* Return unique_ptr from cAtomicUniquePtr::exchange

* cWorld now calls entity cEntity::OnAddToWorld and cEntity::OnRemoveFromWorld.

Allows broadcasting entities added to the world from the world's tick thread.
This also factors out some common code from cEntity::DoMoveToWorld and cEntity::Initialize.

As a consequence, cEntity::Destroy(false) (i.e. Destroying the entity without broadcasting) is impossible.
This isn't used anywhere in Cuberite so it's now deprecated.

* Update entity position after removing it from the world.
Fixes broadcasts being sent to the wrong chunk.

* Fix style

* cEntity: Update LastSentPosition when sending spawn packet

* Add Wno-deprecated-declarations to the lua bindings

* Kill uses of ScheduleMoveToWorld

src/Entities/ExpOrb.cpp

@@ -49,7 +49,7 @@ void cExpOrb::Tick(std::chrono::milliseconds a_Dt, cChunk & a_Chunk)
 			a_Player.DeltaExperience(m_Reward);
 
 			m_World->BroadcastSoundEffect("entity.experience_orb.pickup", GetPosition(), 0.5f, (0.75f + (static_cast<float>((GetUniqueID() * 23) % 32)) / 64));
-			Destroy(true);
+			Destroy();
 			return true;
 		}
 
@@ -84,7 +84,7 @@ void cExpOrb::Tick(std::chrono::milliseconds a_Dt, cChunk & a_Chunk)
 	m_Timer += a_Dt;
 	if (m_Timer >= std::chrono::minutes(5))
 	{
-		Destroy(true);
+		Destroy();
 	}
 }
 
@@ -96,7 +96,7 @@ bool cExpOrb::DoTakeDamage(TakeDamageInfo & a_TDI)
 {
 	if (a_TDI.DamageType == dtCactusContact)
 	{
-		Destroy(true);
+		Destroy();
 		return true;
 	}