Update iterator synthax to be compatible with cpp17 (#3033)

std::iterator is deprecated in cpp17 thus in order to be able to upgrade
to cpp17 if needed we manually define the relevant types for iterator.
See https://www.fluentcpp.com/2018/05/08/std-iterator-deprecated/ for
more details.

src/core/RizinCpp.h

@@ -71,8 +71,15 @@ private:
     const RzPVector *const vec;
 
 public:
-    class iterator : public std::iterator<std::input_iterator_tag, T *>
+    class iterator
     {
+    public:
+        using iterator_category = std::input_iterator_tag;
+        using value_type = T *;
+        using difference_type = ptrdiff_t;
+        using pointer = T **;
+        using reference = T *&;
+
     private:
         T **p;
 
@@ -107,8 +114,15 @@ private:
     const RzList *const list;
 
 public:
-    class iterator : public std::iterator<std::input_iterator_tag, T *>
+    class iterator
     {
+    public:
+        using iterator_category = std::input_iterator_tag;
+        using value_type = T *;
+        using difference_type = ptrdiff_t;
+        using pointer = T **;
+        using reference = T *&;
+
     private:
         RzListIter *iter;