Cleanup includes

Reorder a few includes, include "position.h" where it was previously missing
and apply include-what-you-use suggestions. Also make the order of the includes
consistent, in the following way:

1. Related header (for .cpp files)
2. A blank line
3. C/C++ headers
4. A blank line
5. All other header files

closes https://github.com/official-stockfish/Stockfish/pull/4763
fixes https://github.com/official-stockfish/Stockfish/issues/4707

No functional change

src/nnue/layers/affine_transform.h

@@ -21,9 +21,9 @@
 #ifndef NNUE_LAYERS_AFFINE_TRANSFORM_H_INCLUDED
 #define NNUE_LAYERS_AFFINE_TRANSFORM_H_INCLUDED
 
+#include <cstdint>
 #include <iostream>
-#include <algorithm>
-#include <type_traits>
+
 #include "../nnue_common.h"
 #include "simd.h"
 

src/nnue/layers/affine_transform_sparse_input.h

@@ -21,10 +21,12 @@
 #ifndef NNUE_LAYERS_AFFINE_TRANSFORM_SPARSE_INPUT_H_INCLUDED
 #define NNUE_LAYERS_AFFINE_TRANSFORM_SPARSE_INPUT_H_INCLUDED
 
-#include <iostream>
 #include <algorithm>
 #include <array>
-#include <type_traits>
+#include <cstdint>
+#include <iostream>
+
+#include "../../bitboard.h"
 #include "../nnue_common.h"
 #include "affine_transform.h"
 #include "simd.h"

src/nnue/layers/clipped_relu.h

@@ -21,6 +21,10 @@
 #ifndef NNUE_LAYERS_CLIPPED_RELU_H_INCLUDED
 #define NNUE_LAYERS_CLIPPED_RELU_H_INCLUDED
 
+#include <algorithm>
+#include <cstdint>
+#include <iosfwd>
+
 #include "../nnue_common.h"
 
 namespace Stockfish::Eval::NNUE::Layers {

src/nnue/layers/sqr_clipped_relu.h

@@ -21,6 +21,10 @@
 #ifndef NNUE_LAYERS_SQR_CLIPPED_RELU_H_INCLUDED
 #define NNUE_LAYERS_SQR_CLIPPED_RELU_H_INCLUDED
 
+#include <algorithm>
+#include <cstdint>
+#include <iosfwd>
+
 #include "../nnue_common.h"
 
 namespace Stockfish::Eval::NNUE::Layers {