Fix name overlaps for lists in chip-tool. (#15119)

Before this change, chip-tool's codegen just puts all the list buffers
on the stack and they all have to survive until we use them, so they
can't be in nested scopes.  They are suffixed with a nesting depth,
but if you have a list of structs that contain lists, the names for
the non-toplevel lists collide with each other.

This change switches over to the setup Darwin and Android already use:
heap-allocate the lists, hand the buffers to an RAII object higher up
on the stack that will free them when we are done, and then we can
scope each allocation and filling of a list in its own scope to limit
the visibility of the individual lists' names and avoid them colliding
with each other.

examples/chip-tool/templates/partials/test_cluster.zapt

@@ -301,6 +301,7 @@ class {{filename}}: public TestCommand
         {{#if isCommand}}
         using RequestType = chip::app::Clusters::{{asUpperCamelCase cluster}}::Commands::{{asUpperCamelCase command}}::Type;
 
+        ListFreer listFreer;
         RequestType request;
         {{#chip_tests_item_parameters}}
         {{>commandValue ns=parent.cluster container=(concat "request." (asLowerCamelCase label)) definedValue=definedValue depth=0}}
@@ -334,6 +335,7 @@ class {{filename}}: public TestCommand
         cluster.Associate({{>device}}, endpoint);
         {{/if}}
 
+        ListFreer listFreer;
         {{#chip_tests_item_parameters}}
         {{zapTypeToEncodableClusterObjectType type ns=parent.cluster}} {{asLowerCamelCase name}}Argument;
         {{>commandValue ns=parent.cluster container=(concat (asLowerCamelCase name) "Argument") definedValue=definedValue depth=0}}

examples/chip-tool/templates/partials/test_cluster_command_value.zapt

@@ -14,13 +14,14 @@
       Similarly, forceNotOptional=true and forceNotNullable=true because we
       have accounted for those already. }}
   {{#if definedValue.length}}
-  {{! This should really do heap-allocation with a function-scope-wide
-      auto-free setup, so we could guarantee no name collisions. }}
-  {{zapTypeToEncodableClusterObjectType type ns=ns forceNotList=true forceNotNullable=true forceNotOptional=true}} {{asLowerCamelCase label}}List_{{depth}}[{{definedValue.length}}];
-  {{#each definedValue}}
-  {{>commandValue ns=../ns container=(concat (asLowerCamelCase ../label) "List_" ../depth "[" @index "]") definedValue=. type=../type depth=(incrementDepth ../depth) parent=../parent}}
-  {{/each}}
-  {{container}} = {{asLowerCamelCase label}}List_{{depth}};
+  {
+    auto * listHolder_{{depth}} = new ListHolder<{{zapTypeToEncodableClusterObjectType type ns=ns forceNotList=true forceNotNullable=true forceNotOptional=true}}>({{definedValue.length}});
+    listFreer.add(listHolder_{{depth}});
+    {{#each definedValue}}
+    {{>commandValue ns=../ns container=(concat "listHolder_" ../depth "->mList[" @index "]") definedValue=. type=../type depth=(incrementDepth ../depth) parent=../parent}}
+    {{/each}}
+    {{container}} = chip::app::DataModel::List<{{zapTypeToEncodableClusterObjectType type ns=ns forceNotList=true forceNotNullable=true forceNotOptional=true}}>(listHolder_{{depth}}->mList, {{definedValue.length}});
+  }
   {{else}}
   {{container}} = chip::app::DataModel::List<{{zapTypeToEncodableClusterObjectType type ns=ns forceNotList=true forceNotNullable=true forceNotOptional=true}}>();
   {{/if}}

examples/chip-tool/templates/tests-commands.zapt

@@ -5,6 +5,7 @@
 #include <commands/tests/TestCommand.h>
 #include <commands/common/CommandInvoker.h>
 #include <lib/core/Optional.h>
+#include <lib/support/CHIPListUtils.h>
 #include <system/SystemClock.h>
 
 #include <math.h> // For INFINITY