Global Plugin Reload: OSS Changes Take II (#9347)

* Carefully move changes from the plugin-cluster-reload branch into this clean branch off master.

* Don't test this at this level, adequately covered in the api level tests

* Change PR link

* go.mod

* Vendoring

* Vendor api/sys_plugins.go

command/commands.go

@@ -447,6 +447,11 @@ func initCommands(ui, serverCmdUi cli.Ui, runOpts *RunOptions) {
 				BaseCommand: getBaseCommand(),
 			}, nil
 		},
+		"plugin reload-status": func() (cli.Command, error) {
+			return &PluginReloadStatusCommand{
+				BaseCommand: getBaseCommand(),
+			}, nil
+		},
 		"policy": func() (cli.Command, error) {
 			return &PolicyCommand{
 				BaseCommand: getBaseCommand(),