Remove an unused partial (#29690)

* Remove an unused partial

Problem:

- `src/app/zap-templates/partials/im_command_handler_cluster_commands.zapt` had
  legacy-preserving code that is now 100% obsolete. The remaining part of it
  that was used can now be inlined in the primary command handling template.

This PR:

- Removed the dead partial and updated templates

Testing done:

- Regenerated ZAP and found no changes to code.

* Restyled by prettier-json

* Fix build

---------

Co-authored-by: tennessee.carmelveilleux@gmail.com <tennessee@google.com>
Co-authored-by: Restyled.io <commits@restyled.io>

build/chip/chip_codegen.cmake

@@ -161,7 +161,6 @@ function(chip_zapgen TARGET_NAME)
             #       out links of template files and zap files and such
             SET(EXTRA_DEPENDENCIES
                 "${CHIP_ROOT}/src/app/zap-templates/partials/header.zapt"
-                "${CHIP_ROOT}/src/app/zap-templates/partials/im_command_handler_cluster_commands.zapt"
                 "${CHIP_ROOT}/src/app/zap-templates/templates/app/access.zapt"
                 "${CHIP_ROOT}/src/app/zap-templates/templates/app/CHIPClusters.zapt"
                 "${CHIP_ROOT}/src/app/zap-templates/templates/app/endpoint_config.zapt"

build/chip/chip_codegen.gni

@@ -141,7 +141,6 @@ template("_chip_build_time_zapgen") {
     #       out links of template files and zap files and such
     _extra_dependencies = [
       "${_partials_dir}/header.zapt",
-      "${_partials_dir}/im_command_handler_cluster_commands.zapt",
 
       # Application templates, actually generating files
       "${_template_dir}/access.zapt",

src/app/zap-templates/app-templates.json

@@ -17,10 +17,6 @@
         {
             "name": "header",
             "path": "partials/header.zapt"
-        },
-        {
-            "name": "im_command_handler_cluster_commands",
-            "path": "partials/im_command_handler_cluster_commands.zapt"
         }
     ],
     "templates": [

src/app/zap-templates/templates/app/im-cluster-command-handler.zapt

@@ -36,7 +36,12 @@ void DispatchServerCommand(CommandHandler * apCommandObj, const ConcreteCommandP
         {
     {{/first}}
         case Commands::{{asUpperCamelCase commandName}}::Id: {
-        {{> im_command_handler_cluster_commands}}
+            Commands::{{asUpperCamelCase commandName}}::DecodableType commandData;
+            TLVError = DataModel::Decode(aDataTlv, commandData);
+            if (TLVError == CHIP_NO_ERROR)
+            {
+                wasHandled = emberAf{{asUpperCamelCase parent.clusterName}}Cluster{{asUpperCamelCase commandName}}Callback(apCommandObj, aCommandPath, commandData);
+            }
             break;
         }
     {{#last}}