Get rid of boilerplate annotations

For 10.0, we introduced Switch Templates to Essentials. For HST components that had no ParametersInfo annotation (like e.g. EssentialsContentComponent), this would not work, because HST requires such an annotation for the Template Composer component dialogs to work. HSTTWO-3248 has been created to remove this need. Once it is available, remove the boilerplate code from EssentialsContentComponent.