Need to update `to_binary` to `to_json_binary` due to depreciation

[artemd24]

According to the cosmwasm_std, the function to_binary is deprecated.

As a result build of the project ends with warning. It would be better to change usage of to_binary to more actual to_json_binary.

[artemd24]

This also applies to from_binary

Link to the code

[ifraixedes]

This change should come with more changes than that. The book says to install cosmwasm-std: 1.0.0-beta8. That version doesn't deprecate to_binary and from_binary.

Even worse that version doesn't have from_json which is the replacement for from_binary