backport-13637
[*] adopt to create and verify sign with pkey hash
[*] add funcs to convert dap_pkey_t <-> char
[*] remove a_hash_type from dap_sign_create , add dap_sign_create_with_hash_type func
Edited by pavel.uhanov
[*] adopt to create and verify sign with pkey hash
[*] add funcs to convert dap_pkey_t <-> char
[*] remove a_hash_type from dap_sign_create , add dap_sign_create_with_hash_type func