In the previous commit `js_module_name = None` was removed from
HTMLSnippet class, because it's not being used by this class, or the
classes that inherit from it. But `js_module_name` is used in
MakoTemplateBlockBase.
Not all classes that inherit from MakoTemplateBlockBase define this
attribute, since the same classes inherit from HTMLSnippet class, which
used to provide a fallback for this attribute. To prevent
`AttributeError`, defining the default value of `None` in
MakoTemplateBlockBase.
- Moving xmodule folder to root as we're dissolving sub-projects of common folder in edx-platform
- More info: https://openedx.atlassian.net/browse/BOM-2579
- -e common/lib/xmodule has been removed from the requirements as xmodule has itself become the part of edx-platform and not being installed through requirements
- The test files common/lib/xmodule/test_files/ have been removed as they are not being used anymore
