Add a const version of List::find

Author: aaronfranke

core/templates/list.h

@@ -415,6 +415,19 @@ class List {
 	/**
 	 * find an element in the list,
 	 */
+	template <typename T_v>
+	const Element *find(const T_v &p_val) const {
+		const Element *it = front();
+		while (it) {
+			if (it->value == p_val) {
+				return it;
+			}
+			it = it->next();
+		}
+
+		return nullptr;
+	}
+
 	template <typename T_v>
 	Element *find(const T_v &p_val) {
 		Element *it = front();