Problem/Motivation
In #2659940: Extension System, Part III: ThemeExtensionList and ThemeEngineExtensionList, the responsibility of managing the list of themes and theme data is moved to \Drupal::service('extension.list.theme'). This issue is a follow up to deprecate ThemeHandlerInterface::rebuildThemeData() and replace it with calls to \Drupal::service('extension.list.theme')->reset() and \Drupal::service('extension.list.theme')->getList()
Proposed resolution
Replace all usages and deprecate ThemeHandlerInterface::rebuildThemeData() and trigger a silenced error. Also, when replacing the usages we should ensure that we don't unnecessarily rebuild the module list.
Remaining tasks
User interface changes
None
API changes
None
Data model changes
None