Games: Use default constructors/destructors

https://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines#cother-other-default-operation-rules

"The compiler is more likely to get the default semantics right and
you cannot implement these functions better than the compiler."

Userland/Games/Minesweeper/Field.cpp

@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2018-2021, Andreas Kling <kling@serenityos.org>
+ * Copyright (c) 2022, the SerenityOS developers.
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
@@ -155,10 +156,6 @@ Field::Field(GUI::Label& flag_label, GUI::Label& time_label, GUI::Button& face_b
     }
 }
 
-Field::~Field()
-{
-}
-
 void Field::set_face(Face face)
 {
     switch (face) {
@@ -530,14 +527,6 @@ void Field::set_single_chording(bool enabled)
     Config::write_bool("Minesweeper", "Game", "SingleChording", m_single_chording);
 }
 
-Square::Square()
-{
-}
-
-Square::~Square()
-{
-}
-
 template<typename Callback>
 void Field::for_each_square(Callback callback)
 {