feat(ffi)!: Add commitment_signature_create and destroy (#3768)

Description
---
Adds to FFI interface:
- `commitment_signature_create_from_bytes`
- `commitment_signature_destroy`

Motivation and Context
---
Required for wallet_import_utxo

How Has This Been Tested?
---

base_layer/wallet_ffi/src/lib.rs

@@ -109,7 +109,7 @@ use rand::rngs::OsRng;
 use tari_common_types::{
     emoji::{emoji_set, EmojiId, EmojiIdError},
     transaction::{TransactionDirection, TransactionStatus, TxId},
-    types::PublicKey,
+    types::{Commitment, PublicKey},
 };
 use tari_comms::{
     multiaddr::Multiaddr,
@@ -876,6 +876,109 @@ pub unsafe extern "C" fn private_key_from_hex(key: *const c_char, error_out: *mu
 
 /// -------------------------------------------------------------------------------------------- ///
 
+/// ------------------------------- Commitment Signature ---------------------------------------///
+
+/// Creates a TariCommitmentSignature from `u`, `v` and `public_nonce` ByteVectors
+///
+/// ## Arguments
+/// `public_nonce_bytes` - The public nonce signature component as a ByteVector
+/// `u_bytes` - The u signature component as a ByteVector
+/// `v_bytes` - The v signature component as a ByteVector
+/// `error_out` - Pointer to an int which will be modified to an error code should one occur, may not be null. Functions
+/// as an out parameter.
+///
+/// ## Returns
+/// `TariCommitmentSignature` - Returns a commitment signature. Note that it will be ptr::null_mut() if any argument is
+/// null or if there was an error with the contents of bytes
+///
+/// # Safety
+/// The ```commitment_signature_destroy``` function must be called when finished with a TariCommitmentSignature to
+/// prevent a memory leak
+#[no_mangle]
+pub unsafe extern "C" fn commitment_signature_create_from_bytes(
+    public_nonce_bytes: *mut ByteVector,
+    u_bytes: *mut ByteVector,
+    v_bytes: *mut ByteVector,
+    error_out: *mut c_int,
+) -> *mut TariCommitmentSignature {
+    let mut error = 0;
+    ptr::swap(error_out, &mut error as *mut c_int);
+    if public_nonce_bytes.is_null() {
+        error = LibWalletError::from(InterfaceError::NullError("public_nonce_bytes".to_string())).code;
+        ptr::swap(error_out, &mut error as *mut c_int);
+        return ptr::null_mut();
+    }
+    if u_bytes.is_null() {
+        error = LibWalletError::from(InterfaceError::NullError("u_bytes".to_string())).code;
+        ptr::swap(error_out, &mut error as *mut c_int);
+        return ptr::null_mut();
+    }
+    if v_bytes.is_null() {
+        error = LibWalletError::from(InterfaceError::NullError("v_bytes".to_string())).code;
+        ptr::swap(error_out, &mut error as *mut c_int);
+        return ptr::null_mut();
+    }
+
+    let nonce = match Commitment::from_bytes(&(*public_nonce_bytes).0) {
+        Ok(nonce) => nonce,
+        Err(e) => {
+            error!(
+                target: LOG_TARGET,
+                "Error creating a nonce commitment from bytes: {:?}", e
+            );
+            error = LibWalletError::from(e).code;
+            ptr::swap(error_out, &mut error as *mut c_int);
+            return ptr::null_mut();
+        },
+    };
+    let u = match TariPrivateKey::from_bytes(&(*u_bytes).0) {
+        Ok(u) => u,
+        Err(e) => {
+            error!(
+                target: LOG_TARGET,
+                "Error creating a Public Key (u) from bytes: {:?}", e
+            );
+            error = LibWalletError::from(e).code;
+            ptr::swap(error_out, &mut error as *mut c_int);
+            return ptr::null_mut();
+        },
+    };
+    let v = match TariPrivateKey::from_bytes(&(*v_bytes).0) {
+        Ok(u) => u,
+        Err(e) => {
+            error!(
+                target: LOG_TARGET,
+                "Error creating a Public Key (v) from bytes: {:?}", e
+            );
+            error = LibWalletError::from(e).code;
+            ptr::swap(error_out, &mut error as *mut c_int);
+            return ptr::null_mut();
+        },
+    };
+
+    let sig = TariCommitmentSignature::new(nonce, u, v);
+    Box::into_raw(Box::new(sig))
+}
+
+/// Frees memory for a TariCommitmentSignature
+///
+/// ## Arguments
+/// `com_sig` - The pointer to a TariCommitmentSignature
+///
+/// ## Returns
+/// `()` - Does not return a value, equivalent to void in C
+///
+/// # Safety
+/// None
+#[no_mangle]
+pub unsafe extern "C" fn commitment_signature_destroy(com_sig: *mut TariCommitmentSignature) {
+    if !com_sig.is_null() {
+        Box::from_raw(com_sig);
+    }
+}
+
+/// -------------------------------------------------------------------------------------------- ///
+
 /// ----------------------------------- Seed Words ----------------------------------------------///
 
 /// Create an empty instance of TariSeedWords

base_layer/wallet_ffi/wallet.h

@@ -170,6 +170,19 @@ struct TariPrivateKey *private_key_from_hex(const char *hex, int *error_out);
 // Frees memory for a TariPrivateKey
 void private_key_destroy(struct TariPrivateKey *pk);
 
+/// -------------------------------- Commitment Signature  --------------------------------------------- ///
+
+// Creates a TariCommitmentSignature from `u`, `v` and `public_nonce` ByteVectors
+struct TariCommitmentSignature *commitment_signature_create_from_bytes(
+    struct ByteVector *public_nonce_bytes,
+    struct ByteVector *u_bytes,
+    struct ByteVector *v_bytes,
+    int *error_out
+);
+
+// Frees memory for a TariCommitmentSignature
+void commitment_signature_destroy(struct TariCommitmentSignature *com_sig);
+
 /// -------------------------------- Seed Words  -------------------------------------------------- ///
 // Create an empty instance of TariSeedWords
 struct TariSeedWords *seed_words_create();