Internal refactoring for compatibility with 32-bit

Removed VmaJsonWriter::WriteSize, ContinueString_Size.

See #293
diff --git a/include/vk_mem_alloc.h b/include/vk_mem_alloc.h
index 5d6b295..4d35f45 100644
--- a/include/vk_mem_alloc.h
+++ b/include/vk_mem_alloc.h
@@ -5487,7 +5487,6 @@
     // Posts next part of an open string. The number is converted to decimal characters.
     void ContinueString(uint32_t n);
     void ContinueString(uint64_t n);
-    void ContinueString_Size(size_t n);
     // Posts next part of an open string. Pointer value is converted to characters
     // using "%p" formatting - shown as hexadecimal number, e.g.: 000000081276Ad00
     void ContinueString_Pointer(const void* ptr);
@@ -5497,7 +5496,6 @@
     // Writes a number value.
     void WriteNumber(uint32_t n);
     void WriteNumber(uint64_t n);
-    void WriteSize(size_t n);
     // Writes a boolean value - false or true.
     void WriteBool(bool b);
     // Writes a null value.
@@ -5522,11 +5520,6 @@
     VmaVector< StackItem, VmaStlAllocator<StackItem> > m_Stack;
     bool m_InsideString;
 
-    // Write size_t for less than 64bits
-    void WriteSize(size_t n, std::integral_constant<bool, false>) { m_SB.AddNumber(static_cast<uint32_t>(n)); }
-    // Write size_t for 64bits
-    void WriteSize(size_t n, std::integral_constant<bool, true>) { m_SB.AddNumber(static_cast<uint64_t>(n)); }
-
     void BeginValue(bool isString);
     void WriteIndent(bool oneLess = false);
 };
@@ -5669,14 +5662,6 @@
     m_SB.AddNumber(n);
 }
 
-void VmaJsonWriter::ContinueString_Size(size_t n)
-{
-    VMA_ASSERT(m_InsideString);
-    // Fix for AppleClang incorrect type casting
-    // TODO: Change to if constexpr when C++17 used as minimal standard
-    WriteSize(n, std::is_same<size_t, uint64_t>{});
-}
-
 void VmaJsonWriter::ContinueString_Pointer(const void* ptr)
 {
     VMA_ASSERT(m_InsideString);
@@ -5708,15 +5693,6 @@
     m_SB.AddNumber(n);
 }
 
-void VmaJsonWriter::WriteSize(size_t n)
-{
-    VMA_ASSERT(!m_InsideString);
-    BeginValue(false);
-    // Fix for AppleClang incorrect type casting
-    // TODO: Change to if constexpr when C++17 used as minimal standard
-    WriteSize(n, std::is_same<size_t, uint64_t>{});
-}
-
 void VmaJsonWriter::WriteBool(bool b)
 {
     VMA_ASSERT(!m_InsideString);
@@ -6465,13 +6441,13 @@
     json.WriteNumber(GetSize());
 
     json.WriteString("UnusedBytes");
-    json.WriteSize(unusedBytes);
+    json.WriteNumber(unusedBytes);
 
     json.WriteString("Allocations");
-    json.WriteSize((uint64_t)allocationCount);
+    json.WriteNumber((uint64_t)allocationCount);
 
     json.WriteString("UnusedRanges");
-    json.WriteSize((uint64_t)unusedRangeCount);
+    json.WriteNumber((uint64_t)unusedRangeCount);
 
     json.WriteString("Suballocations");
     json.BeginArray();
@@ -16012,7 +15988,7 @@
                         {
                             json.WriteString("Name");
                             json.BeginString();
-                            json.ContinueString_Size((uint64_t)index++);
+                            json.ContinueString((uint64_t)index++);
                             if (pool->GetName())
                             {
                                 json.ContinueString(" - ");