As part of making the new courseware experience the
default for staff, the LMS /jump_to/ links that are
exposed by the Course Blocks API via the `lms_web_url`
field will soon direct users to whichever experience
is active to them (instead of always directing to
the legacy experience & relying on the learner
redirect).
Because of this, the MFE can no longer rely on
`lms_web_url` to land a staff user to the legacy
experience. However, the aformentioned change
will also introduce a `legacy_web_url` field
to the API, which we *can* use for this purpose.
TNL-7796
to redirect to the current unit’s lmsWebUrl if the MFE is disabled
If we receive an error_code of 'microfrontend_disabled',
go to the equivalent unit in the LMS experience.
Fixes: TNL-7362
Co-authored-by: stvn <stvn@mit.edu>
