Binary strict types (#969)

* Some Binary cleanup, type-hints and strict types
yes, I know this is very crashy... that's good, because it highlights unexpected behaviour

* added some default values

src/pocketmine/network/mcpe/protocol/AddEntityPacket.php

@@ -38,8 +38,8 @@ class AddEntityPacket extends DataPacket{
 	public $speedX;
 	public $speedY;
 	public $speedZ;
-	public $yaw;
-	public $pitch;
+	public $yaw = 0.0;
+	public $pitch = 0.0;
 	/** @var Attribute[] */
 	public $attributes = [];
 	public $metadata = [];

src/pocketmine/network/mcpe/protocol/AvailableCommandsPacket.php

@@ -29,7 +29,7 @@ class AvailableCommandsPacket extends DataPacket{
 	const NETWORK_ID = ProtocolInfo::AVAILABLE_COMMANDS_PACKET;
 
 	public $commands; //JSON-encoded command data
-	public $unknown;
+	public $unknown = "";
 
 	public function decode(){
 		$this->commands = $this->getString();

src/pocketmine/network/mcpe/protocol/ContainerSetSlotPacket.php

@@ -31,10 +31,10 @@ class ContainerSetSlotPacket extends DataPacket{
 
 	public $windowid;
 	public $slot;
-	public $hotbarSlot;
+	public $hotbarSlot = 0;
 	/** @var Item */
 	public $item;
-	public $selectSlot;
+	public $selectSlot = 0;
 
 	public function decode(){
 		$this->windowid = $this->getByte();

src/pocketmine/network/mcpe/protocol/DataPacket.php

@@ -19,6 +19,8 @@
  *
 */
 
+declare(strict_types=1);
+
 namespace pocketmine\network\mcpe\protocol;
 
 #include <rules/DataPacket.h>

src/pocketmine/network/mcpe/protocol/EntityEventPacket.php

@@ -50,19 +50,19 @@ class EntityEventPacket extends DataPacket{
 
 	public $eid;
 	public $event;
-	public $unknown;
+	public $data = 0;
 
 	public function decode(){
 		$this->eid = $this->getEntityRuntimeId();
 		$this->event = $this->getByte();
-		$this->unknown = $this->getVarInt();
+		$this->data = $this->getVarInt();
 	}
 
 	public function encode(){
 		$this->reset();
 		$this->putEntityRuntimeId($this->eid);
 		$this->putByte($this->event);
-		$this->putVarInt($this->unknown);
+		$this->putVarInt($this->data);
 	}
 
 	public function handle(NetworkSession $session) : bool{

src/pocketmine/network/mcpe/protocol/MovePlayerPacket.php

@@ -43,7 +43,7 @@ class MovePlayerPacket extends DataPacket{
 	public $pitch;
 	public $mode = self::MODE_NORMAL;
 	public $onGround;
-	public $ridingEid;
+	public $ridingEid = 0;
 	public $int1 = 0;
 	public $int2 = 0;