Revert "Fix sparse trait codegen for nested collections in JSON and CBOR deserializers (#3756)"

This reverts commit cd93e74.

Author: pulimsr

tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/cbor/CborDecodeListValue.vm

@@ -166,11 +166,7 @@ if(peekType_${recursionDepth}.has_value()){
     #end
 #elseif($shapeMember.list)
     #set($template.nestedShapeMember = $shapeMember.listMember.shape)
-#if($shapeMember.sparse)
-    auto nestedList_${recursionDepth} = Vector<Aws::Crt::Optional<$CppViewHelper.computeCppType($template.nestedShapeMember)>>();
-#else
     auto nestedList_${recursionDepth} = Vector<$CppViewHelper.computeCppType($template.nestedShapeMember)>();
-#end
     auto peekType_${recursionDepth} = decoder->PeekType();
     if (peekType_${recursionDepth}.has_value() && (peekType_${recursionDepth}.value() == CborType::ArrayStart || peekType_${recursionDepth}.value() == CborType::IndefArrayStart))
     {
@@ -217,11 +213,7 @@ if(peekType_${recursionDepth}.has_value()){
     }
 #elseif($shapeMember.map)
     #set($template.nestedShapeMember = $shapeMember.mapValue.shape)
-#if($shapeMember.sparse)
-    auto nestedMap_${recursionDepth} = Map<Aws::String, Aws::Crt::Optional<$CppViewHelper.computeCppType($template.nestedShapeMember)>>();
-#else
     auto nestedMap_${recursionDepth} = Map<Aws::String, $CppViewHelper.computeCppType($template.nestedShapeMember)>();
-#end
     auto peekType_${recursionDepth} = decoder->PeekType();
     if (peekType_${recursionDepth}.has_value() && (peekType_${recursionDepth}.value() == CborType::MapStart || peekType_${recursionDepth}.value() == CborType::IndefMapStart))
     {

tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/cbor/CborDecodeMapValue.vm

@@ -169,11 +169,7 @@ if(peekType_${recursionDepth}){
     #end
 #elseif($shapeMember.map)
     #set($template.nestedShapeMember = $shapeMember.mapValue.shape)
-#if($shapeMember.sparse)
-    auto nestedMap_${recursionDepth} = Map<Aws::String, Aws::Crt::Optional<$CppViewHelper.computeCppType($template.nestedShapeMember)>>();
-#else
     auto nestedMap_${recursionDepth} = Map<Aws::String, $CppViewHelper.computeCppType($template.nestedShapeMember)>();
-#end
     auto peekType_${recursionDepth} = decoder->PeekType();
     if (peekType_${recursionDepth}.has_value() && (peekType_${recursionDepth}.value() == CborType::MapStart || peekType_${recursionDepth}.value() == CborType::IndefMapStart))
     {
@@ -218,11 +214,7 @@ if(peekType_${recursionDepth}){
     }
 #elseif($shapeMember.list)
     #set($template.nestedShapeMember = $shapeMember.listMember.shape)
-#if($shapeMember.sparse)
-    auto nestedList_${recursionDepth} = Vector<Aws::Crt::Optional<$CppViewHelper.computeCppType($template.nestedShapeMember)>>();
-#else
     auto nestedList_${recursionDepth} = Vector<$CppViewHelper.computeCppType($template.nestedShapeMember)>();
-#end
     auto peekType_${recursionDepth} = decoder->PeekType();
     if (peekType_${recursionDepth}.has_value() && (peekType_${recursionDepth}.value() == CborType::ArrayStart || peekType_${recursionDepth}.value() == CborType::IndefArrayStart))
     {

tools/code-generation/generator/src/main/resources/com/amazonaws/util/awsclientgenerator/velocity/cpp/json/ModelInternalMapOrListJsonDeserializer.vm

@@ -18,11 +18,7 @@
 #end
 #if($template.recursionDepth > 1)
 #set($template.containerVar = ${template.lowerCaseVarName} + "Map")
-#if($template.currentShape.sparse)
-  ${template.currentSpaces}Aws::Map<${CppViewHelper.computeCppType($template.currentShape.mapKey.shape)}, Aws::Crt::Optional<${CppViewHelper.computeCppType($template.currentShape.mapValue.shape)}>> ${template.lowerCaseVarName}Map;
-#else
   ${template.currentSpaces}Aws::Map<${CppViewHelper.computeCppType($template.currentShape.mapKey.shape)}, ${CppViewHelper.computeCppType($template.currentShape.mapValue.shape)}> ${template.lowerCaseVarName}Map;
-#end
 #end
   ${template.currentSpaces}for(auto& ${template.lowerCaseVarName}Item : ${template.lowerCaseVarName}JsonMap)
   ${template.currentSpaces}{
@@ -88,11 +84,7 @@
 #end
 #if($template.recursionDepth > 1)
 #set($template.containerVar = ${template.lowerCaseVarName} + "List")
-#if($template.currentShape.sparse)
-  ${template.currentSpaces}Aws::Vector<Aws::Crt::Optional<${CppViewHelper.computeCppType($template.currentShape.listMember.shape)}>> ${template.lowerCaseVarName}List;
-#else
   ${template.currentSpaces}Aws::Vector<${CppViewHelper.computeCppType($template.currentShape.listMember.shape)}> ${template.lowerCaseVarName}List;
-#end
   ${template.currentSpaces}${template.lowerCaseVarName}List.reserve((size_t)${template.lowerCaseVarName}JsonList.GetLength());
 #end
   ${template.currentSpaces}for(unsigned ${template.lowerCaseVarName}Index = 0; ${template.lowerCaseVarName}Index < ${template.lowerCaseVarName}JsonList.GetLength(); ++${template.lowerCaseVarName}Index)