Rename `CollectionData.hpp` to `CollectionIterator.hpp`

I also removed some of the unused include statements.

extras/tests/JsonDocument/constructor.cpp

@@ -8,8 +8,6 @@
 #include "Allocators.hpp"
 #include "Literals.hpp"
 
-using ArduinoJson::detail::addPadding;
-
 TEST_CASE("JsonDocument constructor") {
   SpyingAllocator spyingAllocator;
 

extras/tests/MixedConfiguration/enable_alignment_0.cpp

@@ -2,6 +2,8 @@
 #define ARDUINOJSON_ENABLE_ALIGNMENT 0
 #include <ArduinoJson.h>
 
+#include <ArduinoJson/Memory/Alignment.hpp>
+
 #include <catch.hpp>
 
 TEST_CASE("ARDUINOJSON_ENABLE_ALIGNMENT == 0") {

extras/tests/MixedConfiguration/enable_alignment_1.cpp

@@ -1,6 +1,8 @@
 #define ARDUINOJSON_ENABLE_ALIGNMENT 1
 #include <ArduinoJson.h>
 
+#include <ArduinoJson/Memory/Alignment.hpp>
+
 #include <catch.hpp>
 
 TEST_CASE("ARDUINOJSON_ENABLE_ALIGNMENT == 1") {

extras/tests/ResourceManager/allocVariant.cpp

@@ -5,6 +5,8 @@
 #include <ArduinoJson.hpp>
 #include <catch.hpp>
 
+#include <ArduinoJson/Memory/Alignment.hpp>
+
 #include "Allocators.hpp"
 
 using namespace ArduinoJson::detail;

src/ArduinoJson/Collection/CollectionImpl.hpp

@@ -4,11 +4,7 @@
 
 #pragma once
 
-#include <ArduinoJson/Collection/CollectionData.hpp>
-#include <ArduinoJson/Memory/Alignment.hpp>
-#include <ArduinoJson/Strings/StringAdapters.hpp>
-#include <ArduinoJson/Variant/VariantCompare.hpp>
-#include <ArduinoJson/Variant/VariantData.hpp>
+#include <ArduinoJson/Variant/VariantImpl.hpp>
 
 ARDUINOJSON_BEGIN_PRIVATE_NAMESPACE
 

src/ArduinoJson/Collection/CollectionData.hpp → src/ArduinoJson/Collection/CollectionIterator.hpp

@@ -4,7 +4,6 @@
 
 #pragma once
 
-#include <ArduinoJson/Memory/MemoryPool.hpp>
 #include <ArduinoJson/Namespace.hpp>
 #include <ArduinoJson/Polyfills/assert.hpp>
 

src/ArduinoJson/Variant/VariantImpl.hpp

@@ -4,7 +4,7 @@
 
 #pragma once
 
-#include <ArduinoJson/Collection/CollectionData.hpp>
+#include <ArduinoJson/Collection/CollectionIterator.hpp>
 #include <ArduinoJson/Memory/ResourceManager.hpp>
 #include <ArduinoJson/Misc/SerializedValue.hpp>
 #include <ArduinoJson/Numbers/convertNumber.hpp>