Add import from YT
upload subtitles into studio: add python side functionality
upload subtitles into studio: add python integration tests
upload subtitles into studio: add python unit tests for utils
Add upload subtitles file + Refactoring
download subtitles into studio: add python side functionality
download subtitles into studio: add python integration tests
download subtitles into studio: add python unit tests for utils functions
Move subtitles to the edit tab
Add tests for CMS.Views.SubtitlesImport
Add tests for CMS.Views.SubtitlesImportFile
Add tests for CMS.Views.SubtitlesImportYT
Add download subtitles button
Add tests for Download button
Port tabs to XBlock
Refactor Module Name
Fix bugs in tabs
Refactor
Add tests for CMS.Views.SubtitlesMessages
Add tests for TabsEditorDescriptor