This attribute is already deprecated for XBlocks in favour of directly
retrieving it like `block.scope_ids.usage_id.context_key`.
This commit also removes some redundant logging code which was omitted in the
Datadog removal in #19420.
- 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
