Withers and builder's setters doesn't work properly for ByteBuf attributes

Shallow equals check always fail because doesn't consider wrappings. It's also related to `TlEncodingUtil#copyAsUnpooled`
Currently, all ByteBuf accessors are returning `.duplicate()` wrap around original buffer for preventing index modifying.
As a way to fix it we can provide a new type of ByteBuf and compare attribute's types