702866b225
This:
1. Deletes XModuleDescriptorToXBlockMixin
2. Deletes `metadata_traslations` and `_translate()` from `XmlParserMixin`,
and all related implementations.
3. Removes translations of deprecated OLX attributes during import/export:
<old_attr> : <new_attr>
- 'slug' : 'url_name'
- 'name' : 'display_name'
- 'id' : 'discussion_id' (Discussion XBlock)
- 'for' : 'discussion_target' (Discussion XBlock)
- 'attempts' : 'max_attempts' (CAPA)
IGNORING FILES
This course gets used to simulate imports of a course that include unnecessary files inside the static assets directory, such as metadata files from Mac OS (filename starts with ._), or backup files from an editor (filename ends with ~). These files do not belong with the content so they should not be imported, and any existing instances should be removed.