[*] Fixed a bug related to getting a dateTime object from a timestamp. Added function to get datum version. Fixed the calling convention and the name of the function to get the size of the datum.

[+] Added functions for checking whether a datum, a declaration token and an emission token, and also added functions for getting wrapper objects dap_chain_datum_token_t, dap_chain_datum_token_emission_t. The function of getting the string representation of the datum type has also been added.