Create an admin-only option to make "de-list" a published casebook

[lizadaly]

As part of allowing more flexibility in publishing states, make it possible for admins to remove a book from the public listing.

Definition of done:

• The book is not visible in the public search catalog even if it is by a verified professor and publlished

Originally posted by @cath9 in https://github.com/harvard-lil/h2o/issues/1717#issuecomment-1478038417

[lizadaly]

@cath9 Should the book also be delisted from Google, or does that not matter here?