feat: add Iterate for hashmap datastructure

datastructure/hashmap/hashmap.go

@@ -93,6 +93,28 @@ func (hm *HashMap) Contains(key any) bool {
 	return node != nil
 }
 
+// Iterate executes iteratee funcation for every key and value pair of hashmap
+func (hm *HashMap) Iterate(iteratee func(key, value any)) {
+	if hm.size > 0 {
+		for _, item := range hm.table {
+			iteratee(item.key, item.value)
+		}
+	}
+}
+
+// Keys returns a slice of the hashmap's keys
+// func (hm *HashMap) Keys() []any {
+// 	keys := make([]any, int(hm.size))
+
+// 	var i int
+// 	for k := range m {
+// 		keys[i] = k
+// 		i++
+// 	}
+
+// 	return keys
+// }
+
 func (hm *HashMap) resize() {
 	hm.capacity <<= 1