Better API specification: ASN1_INTEGER_*

[RoLex]

According to: https://docs.openssl.org/3.3/man3/ASN1_INTEGER_get_int64/

This:

  ASN1_INTEGER_get: function(a: PASN1_BIT_STRING): LongInt; cdecl;
  ASN1_INTEGER_set: function(a: PASN1_BIT_STRING; v: LongInt): Integer; cdecl;

Needs to be declared as this:

  ASN1_INTEGER_get: function(a: PASN1_INTEGER): LongInt; cdecl;
  ASN1_INTEGER_set: function(a: PASN1_INTEGER; v: LongInt): Integer; cdecl;

Both PASN1_BIT_STRING and PASN1_INTEGER are simple pointers, but it's good for coders to know what is expected by function.