tlb support Unmarshal a cell to a message struct and opCode

[studyzy]

Currently, tlb only have: func Unmarshal(c *boc.Cell, o any) error but when the Cell is a message with OpCode, I must define a struct with OpCode uint32.

What I want?

I want to have a new function:

func UnmarshalMessage(c *boc.Cell, o any) (opCode uint32, err error)

So I don't need define new message struct with OpCode.