Remove learning_format, use delivery for search filter/facet

[mbertrand]

What are the relevant tickets?

Part 2 of https://github.com/mitodl/hq/issues/5126, depends on mitodl/course-search-utils#123

Description (What does it do?)

• Uses an updated version of course-search-utils (Add delivery as a query/facet option course-search-utils#123), which needs to be merged before this one. Once it is merged and released, then this PR will be updated to use the new release version. Currently it is pinned to the course-search-utils PR commit.
• Removes the learning_format field from the LearningResource model
• Renames learning_format to delivery in the Profile model
• Removes "learning_format" from the ETL pipelines
• Updates the frontend to use "delivery" instead of "learning_format" for filtering and facets

How can this be tested?

• Run some searches, with and without using the "Format" facet, everything should work as expected.
• Update your preferred format for your user profile, everything should work as expected.

Additional Context

[shanbady]

Seems like this factory attribute still remains but otherwise looks good

[mbertrand]

@shanbady that "format" factory attribute is for LearningResourceOfferor.format which is not quite the same thing as LearningResource.learning_format. I made a bunch of changes based on feedback from Simone, because some more planning has to go into how the switchover to "delivery" will be presented on the front end:

• Removed all "offline" values from courses via a migration and updated the OCW ETL pipeline to not add it unless OCW_OFFLINE_DELIVERY=True (default=False)
• Reverted "Format"->"Delivery" frontend text changes
• Updated package.json and yarn.lock to use the official new version of course-search-utils

[abeglova]

lgtm