PLAT-1884 Replace deprecated xblock.fragment usage

cms/djangoapps/contentstore/views/item.py

cms/djangoapps/contentstore/views/preview.py

cms/djangoapps/contentstore/views/tests/test_item.py

cms/lib/xblock/authoring_mixin.py

cms/lib/xblock/tagging/tagging.py

common/lib/xmodule/xmodule/conditional_module.py

common/lib/xmodule/xmodule/html_module.py

common/lib/xmodule/xmodule/imageannotation_module.py

common/lib/xmodule/xmodule/library_content_module.py

common/lib/xmodule/xmodule/library_root_xblock.py

common/lib/xmodule/xmodule/mako_module.py

common/lib/xmodule/xmodule/modulestore/tests/test_asides.py

...odule/xmodule/modulestore/tests/test_mixed_modulestore.py

common/lib/xmodule/xmodule/randomize_module.py

common/lib/xmodule/xmodule/seq_module.py

common/lib/xmodule/xmodule/split_test_module.py

common/lib/xmodule/xmodule/studio_editable.py

common/lib/xmodule/xmodule/tests/test_library_content.py

common/lib/xmodule/xmodule/tests/test_library_root.py

common/lib/xmodule/xmodule/textannotation_module.py