Add support for staking module tx MsgCreateValidator (#14)

Part of [laconicd testnet validator enrollment](https://www.notion.so/laconicd-testnet-validator-enrollment-6fc1d3cafcc64fef8c5ed3affa27c675)

Co-authored-by: Prathamesh Musale <prathamesh.musale0@gmail.com>
Co-authored-by: Adw8 <adwaitgharpure@gmail.com>
Reviewed-on: #14

src/screens/ApproveTransaction.tsx

@@ -258,6 +258,13 @@ const ApproveTransaction = ({ route }: ApproveTransactionProps) => {
     navigation.navigate('Laconic');
   };
 
+  const replacer = (key: string, value: any): any => {
+    if (value instanceof Uint8Array) {
+      return Buffer.from(value).toString('hex');
+    }
+    return value;
+  };
+
   return (
     <>
       <ScrollView contentContainerStyle={styles.approveTransaction}>
@@ -282,7 +289,7 @@ const ApproveTransaction = ({ route }: ApproveTransactionProps) => {
         </Text>
         <View style={styles.messageBody}>
           <Text variant="bodyLarge">
-            {JSON.stringify(transactionMessage, null, 2)}
+            {JSON.stringify(transactionMessage, replacer, 2)}
           </Text>
         </View>
         <>