pluginScopeKeys(plugin) {
    const id = plugin.id;
    const type = this.type;
    return cachedKeys(`${type}-plugin-${id}`,
      () => [[
        `plugins.${id}`,
        ...plugin.additionalOptionScopes || [],
      ]]);
  }
Returns the options scope keys for resolving plugin options.
@param {{id: string, additionalOptionScopes?: string[]}} plugin
@return {string[][]}