Revert "[BD-13] Let ModuleSystem use UserService"

[ormsbee]

Reverts edx/edx-platform#28440

FYI @pomegranited and @symbolist: Reverting over issues around anonymous_student_id values. Will update with more information shortly.

[connorhaugh]

Looks like it matches the og PR. lgtm. i will keep an ear to the ground incase revert causes problems.

[edx-status-bot]

Your PR has finished running tests. There were no failures.

[edx-pipeline-bot]

EdX Release Notice: This PR has been deployed to the staging environment in preparation for a release to production.

[pomegranited]

@ormsbee bummer :(

Could it have to do with this change? We dropped the is_pure_xblock check because that should be true for everything now, but maybe it's not? CC @symbolist

[edx-pipeline-bot]

EdX Release Notice: This PR has been deployed to the production environment.

[pomegranited]

Hi @ormsbee , I'm away until 18 Oct, but would like to address this when I return.
Do you have any more information about what issue this caused in production?

[ormsbee]

@pomegranited: I'll post up an example before you get back. Thank you.

[pomegranited]

Hi @ormsbee 👋 Do you have any more information about this issue? Thank you!