AK: Add a non-const overload to HapMap::get()

Additionally, the const version of get() returns Optional<ConstPeekType>
for smart pointers.

For example, if the value in the HashMap is OwnPtr<u32>,
HashMap::get() const returns Optional<const u32*>.

Author: itamar8910

AK/HashMap.h

@@ -95,7 +95,23 @@ class HashMap {
 
     void ensure_capacity(size_t capacity) { m_table.ensure_capacity(capacity); }
 
-    Optional<typename Traits<V>::PeekType> get(const K& key) const
+    Optional<typename Traits<V>::PeekType> get(const K& key) const requires(!IsPointer<typename Traits<V>::PeekType>)
+    {
+        auto it = find(key);
+        if (it == end())
+            return {};
+        return (*it).value;
+    }
+
+    Optional<typename Traits<V>::ConstPeekType> get(const K& key) const requires(IsPointer<typename Traits<V>::PeekType>)
+    {
+        auto it = find(key);
+        if (it == end())
+            return {};
+        return (*it).value;
+    }
+
+    Optional<typename Traits<V>::PeekType> get(const K& key) requires(!IsConst<typename Traits<V>::PeekType>)
     {
         auto it = find(key);
         if (it == end())