Core/Objects: fixed buffer initialization of PackedGuid (#462)

* Core/ObjectGuid: Properly initialize PackedGuid buffer

* use correct initializer for buffer initialization

* correct array initialization in PackedGuid constructors

---------

Co-authored-by: Ovahlord <18347559+Ovahlord@users.noreply.github.com>

src/server/game/Entities/Object/ObjectGuid.cpp

@@ -86,6 +86,7 @@ ObjectGuid ObjectGuid::MapSpecific(HighGuid type, uint32 entry, LowType counter)
 void PackedGuid::Set(ObjectGuid guid)
 {
     _packedSize = 1;
+    _packedGuid = { };
     uint64 raw = guid.GetRawValue();
     for (uint8 i = 0; i < 8; ++i)
     {

src/server/game/Entities/Object/ObjectGuid.h

@@ -299,8 +299,8 @@ class TC_GAME_API PackedGuid
     friend TC_GAME_API ByteBuffer& operator<<(ByteBuffer& buf, PackedGuid const& guid);
 
     public:
-        explicit PackedGuid() : _packedSize(1), _packedGuid() { }
-        explicit PackedGuid(ObjectGuid guid) { Set(guid); }
+        explicit PackedGuid() : _packedSize(1), _packedGuid({}) { }
+        explicit PackedGuid(ObjectGuid guid) : _packedSize(1), _packedGuid({}) { Set(guid); }
 
         void Set(ObjectGuid guid);