Cleanup external_marketing_url field from CourseRun model

[arslanashraf7]

Description

In #2628 we migrated external_marketing_url from CourseRun model into Courseware model in CMS. We could not remove these fields in the original PR because the data migration depends on it. So this has to be a separate PR that should be merged once the original PR is live in Production.

Expected Behavior

• external_marketing_url field from CourseRun is removed along with any of its possible usages

[cachob]

@arslanashraf7 I noticed that the values in this field did not port over to the CMS field. The external url fields in the CMS are all blank:

https://xpro.mit.edu/cms/pages/506/edit/

Is there way to backfill these fields?

[arslanashraf7]

@arslanashraf7 I noticed that the values in this field did not port over to the CMS field. The external url fields in the CMS are all blank:

When I checked, I could see the values back filled e.g. for https://xpro.mit.edu/cms/pages/408/edit/. Was there a value set for this in the course run?

Is there way to backfill these fields?

We can manually backfill them.

[cachob]

My mistake - I was looking at the course page for this course and not the program page: https://xpro.mit.edu/cms/pages/381/edit/

[arslanashraf7]

Closing, Deployed on prod via #2639