Be a bit more consistent about type handling in ZAP templates. (#10718)

* Instead of checking for "item.type == 'boolean'", which would not
  work right for command args (where the type is "BOOLEAN"), go
  through our normal type-mapping machinery and then use the resulting
  uniform output.

* Add "single" to our atomic type overrides and remove manual handling
  of it in zapTypeToClusterObjectType.  This incidentally fixes all
  the generated accessors for single-typed attributes.

* Fix a debugging exception message to include the value that could not be
  handled in a more-correct way.

Author: bzbarsky-apple

src/app/zap-templates/common/ClusterTestGeneration.js

@@ -426,7 +426,7 @@ function chip_tests_item_parameters(options)
             value = new Boolean(value);
             break;
           default:
-            throw new Error('Unsupported value: ', value);
+            throw new Error('Unsupported value: ' + JSON.stringify(value));
           }
         }
 

src/app/zap-templates/common/ClustersHelper.js

@@ -196,10 +196,6 @@ function asChipCallback(item)
     return { name : 'List', type : null };
   }
 
-  if (item.type == 'boolean') {
-    return { name : 'Boolean', type : 'bool' };
-  }
-
   const basicType = ChipTypesHelper.asBasicType(item.chipType);
   switch (basicType) {
   case 'int8_t':
@@ -212,6 +208,8 @@ function asChipCallback(item)
   case 'uint32_t':
   case 'uint64_t':
     return { name : 'Int' + basicType.replace(/[^0-9]/g, '') + 'u', type : basicType };
+  case 'bool':
+    return { name : 'Boolean', type : 'bool' };
   default:
     return { name : 'Unsupported', type : null };
   }

src/app/zap-templates/common/override.js

@@ -20,6 +20,8 @@ function atomicType(arg)
   switch (arg.name) {
   case 'boolean':
     return 'bool';
+  case 'single':
+    return 'float';
   case 'int40s':
   case 'int48s':
   case 'int56s':

src/app/zap-templates/templates/app/helper.js

@@ -350,10 +350,6 @@ function asMEI(prefix, suffix)
  */
 async function zapTypeToClusterObjectType(type, isDecodable, options)
 {
-  if (type == 'single') {
-    return 'float';
-  }
-
   async function fn(pkgId)
   {
     const ns          = options.hash.ns ? ('chip::app::Clusters::' + asUpperCamelCase(options.hash.ns) + '::') : '';