Add: Nasl builtin functions for Kerberos support

This includes:
- krb5_error_code_to_string
- krb5_find_kdc
- krb5_gss_init
- krb5_gss_prepare_context
- krb5_gss_session_key
- krb5_gss_update_context
- krb5_gss_update_context_needs_more
- krb5_gss_update_context_out
- krb5_is_failure
- krb5_is_success

Author: Kraemii

rust/Cargo.lock

@@ -4,6 +4,8 @@
 
 use thiserror::Error;
 
+#[cfg(feature = "nasl-c-lib")]
+use crate::nasl::builtin::krb5::Krb5Error;
 use crate::nasl::prelude::*;
 use crate::nasl::utils::error::FnErrorKind;
 
@@ -56,6 +58,9 @@ pub enum BuiltinError {
     RawIp(RawIpError),
     #[error("{0}")]
     Preference(String),
+    #[cfg(feature = "nasl-c-lib")]
+    #[error("{0}")]
+    Krb5(Krb5Error),
 }
 
 macro_rules! builtin_error_variant (
@@ -104,3 +109,6 @@ builtin_error_variant!(SnmpError, Snmp);
 
 #[cfg(feature = "nasl-builtin-raw-ip")]
 builtin_error_variant!(RawIpError, RawIp);
+
+#[cfg(feature = "nasl-c-lib")]
+builtin_error_variant!(Krb5Error, Krb5);